diff --git a/src/battle-scene.ts b/src/battle-scene.ts
index a759cbb84c2..f676ba63306 100644
--- a/src/battle-scene.ts
+++ b/src/battle-scene.ts
@@ -1526,8 +1526,6 @@ export default class BattleScene extends SceneBase {
       this.currentBattle.mysteryEncounterType = mysteryEncounterType;
     }
 
-    //this.pushPhase(new TrainerMessageTestPhase(this, TrainerType.RIVAL, TrainerType.RIVAL_2, TrainerType.RIVAL_3, TrainerType.RIVAL_4, TrainerType.RIVAL_5, TrainerType.RIVAL_6));
-
     if (!waveIndex && lastBattle) {
       const isWaveIndexMultipleOfTen = !(lastBattle.waveIndex % 10);
       const isEndlessOrDaily = this.gameMode.hasShortBiomes || this.gameMode.isDaily;
diff --git a/src/phases/add-enemy-buff-modifier-phase.ts b/src/phases/add-enemy-buff-modifier-phase.ts
index 7d91e64382a..16ed78e6d0d 100644
--- a/src/phases/add-enemy-buff-modifier-phase.ts
+++ b/src/phases/add-enemy-buff-modifier-phase.ts
@@ -9,10 +9,6 @@ import { Phase } from "#app/phase";
 import { globalScene } from "#app/global-scene";
 
 export class AddEnemyBuffModifierPhase extends Phase {
-  constructor() {
-    super();
-  }
-
   start() {
     super.start();
 
diff --git a/src/phases/attempt-run-phase.ts b/src/phases/attempt-run-phase.ts
index dab5b8789da..e5691f5fb8e 100644
--- a/src/phases/attempt-run-phase.ts
+++ b/src/phases/attempt-run-phase.ts
@@ -1,10 +1,10 @@
 import { applyAbAttrs, applyPreLeaveFieldAbAttrs, PreLeaveFieldAbAttr, RunSuccessAbAttr } from "#app/data/ability";
-import { Stat } from "#app/enums/stat";
-import { StatusEffect } from "#app/enums/status-effect";
+import { Stat } from "#enums/stat";
+import { StatusEffect } from "#enums/status-effect";
 import type { PlayerPokemon, EnemyPokemon } from "#app/field/pokemon";
 import type Pokemon from "#app/field/pokemon";
 import i18next from "i18next";
-import * as Utils from "#app/utils";
+import { NumberHolder } from "#app/utils";
 import { BattleEndPhase } from "./battle-end-phase";
 import { NewBattlePhase } from "./new-battle-phase";
 import { PokemonPhase } from "./pokemon-phase";
@@ -22,7 +22,7 @@ export class AttemptRunPhase extends PokemonPhase {
 
     const playerPokemon = this.getPokemon();
 
-    const escapeChance = new Utils.NumberHolder(0);
+    const escapeChance = new NumberHolder(0);
 
     this.attemptRunAway(playerField, enemyField, escapeChance);
 
@@ -63,7 +63,7 @@ export class AttemptRunPhase extends PokemonPhase {
     this.end();
   }
 
-  attemptRunAway(playerField: PlayerPokemon[], enemyField: EnemyPokemon[], escapeChance: Utils.NumberHolder) {
+  attemptRunAway(playerField: PlayerPokemon[], enemyField: EnemyPokemon[], escapeChance: NumberHolder) {
     /** Sum of the speed of all enemy pokemon on the field */
     const enemySpeed = enemyField.reduce(
       (total: number, enemyPokemon: Pokemon) => total + enemyPokemon.getStat(Stat.SPD),
diff --git a/src/phases/battle-end-phase.ts b/src/phases/battle-end-phase.ts
index e6a0c66548e..ff17b17ab8b 100644
--- a/src/phases/battle-end-phase.ts
+++ b/src/phases/battle-end-phase.ts
@@ -26,13 +26,15 @@ export class BattleEndPhase extends BattlePhase {
       return true;
     });
     // `phaseQueuePrepend` is private, so we have to use this inefficient loop.
-    while (globalScene.tryRemoveUnshiftedPhase(phase => {
-      if (phase instanceof BattleEndPhase) {
-        this.isVictory ||= phase.isVictory;
-        return true;
-      }
-      return false;
-    })) {}
+    while (
+      globalScene.tryRemoveUnshiftedPhase(phase => {
+        if (phase instanceof BattleEndPhase) {
+          this.isVictory ||= phase.isVictory;
+          return true;
+        }
+        return false;
+      })
+    ) {}
 
     globalScene.gameData.gameStats.battles++;
     if (
diff --git a/src/phases/battle-phase.ts b/src/phases/battle-phase.ts
index 72bcc85bc62..d70b3909639 100644
--- a/src/phases/battle-phase.ts
+++ b/src/phases/battle-phase.ts
@@ -3,13 +3,13 @@ import { TrainerSlot } from "#enums/trainer-slot";
 import { Phase } from "#app/phase";
 
 export class BattlePhase extends Phase {
-  constructor() {
-    super();
-  }
-
   showEnemyTrainer(trainerSlot: TrainerSlot = TrainerSlot.NONE): void {
-    const sprites = globalScene.currentBattle.trainer?.getSprites()!; // TODO: is this bang correct?
-    const tintSprites = globalScene.currentBattle.trainer?.getTintSprites()!; // TODO: is this bang correct?
+    if (!globalScene.currentBattle.trainer) {
+      console.warn("Enemy trainer is missing!");
+      return;
+    }
+    const sprites = globalScene.currentBattle.trainer.getSprites();
+    const tintSprites = globalScene.currentBattle.trainer.getTintSprites();
     for (let i = 0; i < sprites.length; i++) {
       const visible = !trainerSlot || !i === (trainerSlot === TrainerSlot.TRAINER) || sprites.length < 2;
       [sprites[i], tintSprites[i]].map(sprite => {
diff --git a/src/phases/berry-phase.ts b/src/phases/berry-phase.ts
index 0048f8cd2f2..e5614739903 100644
--- a/src/phases/berry-phase.ts
+++ b/src/phases/berry-phase.ts
@@ -4,7 +4,7 @@ import { BerryUsedEvent } from "#app/events/battle-scene";
 import { getPokemonNameWithAffix } from "#app/messages";
 import { BerryModifier } from "#app/modifier/modifier";
 import i18next from "i18next";
-import * as Utils from "#app/utils";
+import { BooleanHolder } from "#app/utils";
 import { FieldPhase } from "./field-phase";
 import { CommonAnimPhase } from "./common-anim-phase";
 import { globalScene } from "#app/global-scene";
@@ -20,7 +20,7 @@ export class BerryPhase extends FieldPhase {
       }, pokemon.isPlayer());
 
       if (hasUsableBerry) {
-        const cancelled = new Utils.BooleanHolder(false);
+        const cancelled = new BooleanHolder(false);
         pokemon.getOpponents().map(opp => applyAbAttrs(PreventBerryUseAbAttr, opp, cancelled));
 
         if (cancelled.value) {
@@ -44,7 +44,7 @@ export class BerryPhase extends FieldPhase {
 
           globalScene.updateModifiers(pokemon.isPlayer());
 
-          applyAbAttrs(HealFromBerryUseAbAttr, pokemon, new Utils.BooleanHolder(false));
+          applyAbAttrs(HealFromBerryUseAbAttr, pokemon, new BooleanHolder(false));
         }
       }
     });
diff --git a/src/phases/common-anim-phase.ts b/src/phases/common-anim-phase.ts
index d32e93ea6aa..5be5e112389 100644
--- a/src/phases/common-anim-phase.ts
+++ b/src/phases/common-anim-phase.ts
@@ -6,13 +6,18 @@ import { PokemonPhase } from "./pokemon-phase";
 
 export class CommonAnimPhase extends PokemonPhase {
   private anim: CommonAnim | null;
-  private targetIndex: number | undefined;
+  private targetIndex?: BattlerIndex;
   private playOnEmptyField: boolean;
 
-  constructor(battlerIndex?: BattlerIndex, targetIndex?: BattlerIndex, anim?: CommonAnim, playOnEmptyField = false) {
+  constructor(
+    battlerIndex?: BattlerIndex,
+    targetIndex?: BattlerIndex,
+    anim: CommonAnim | null = null,
+    playOnEmptyField = false,
+  ) {
     super(battlerIndex);
 
-    this.anim = anim!; // TODO: is this bang correct?
+    this.anim = anim;
     this.targetIndex = targetIndex;
     this.playOnEmptyField = playOnEmptyField;
   }
diff --git a/src/phases/damage-anim-phase.ts b/src/phases/damage-anim-phase.ts
index 703cd3d160e..696a2e55b6f 100644
--- a/src/phases/damage-anim-phase.ts
+++ b/src/phases/damage-anim-phase.ts
@@ -10,11 +10,16 @@ export class DamageAnimPhase extends PokemonPhase {
   private damageResult: DamageResult;
   private critical: boolean;
 
-  constructor(battlerIndex: BattlerIndex, amount: number, damageResult?: DamageResult, critical = false) {
+  constructor(
+    battlerIndex: BattlerIndex,
+    amount: number,
+    damageResult: DamageResult = HitResult.EFFECTIVE,
+    critical = false,
+  ) {
     super(battlerIndex);
 
     this.amount = amount;
-    this.damageResult = damageResult || HitResult.EFFECTIVE;
+    this.damageResult = damageResult;
     this.critical = critical;
   }
 
diff --git a/src/phases/egg-hatch-phase.ts b/src/phases/egg-hatch-phase.ts
index 49a408e8699..07eeeb0f8ae 100644
--- a/src/phases/egg-hatch-phase.ts
+++ b/src/phases/egg-hatch-phase.ts
@@ -11,7 +11,7 @@ import PokemonInfoContainer from "#app/ui/pokemon-info-container";
 import { Mode } from "#app/ui/ui";
 import i18next from "i18next";
 import SoundFade from "phaser3-rex-plugins/plugins/soundfade";
-import * as Utils from "#app/utils";
+import { fixedInt, getFrameMs, randInt } from "#app/utils";
 import type { EggLapsePhase } from "./egg-lapse-phase";
 import type { EggHatchData } from "#app/data/egg-hatch-data";
 import { doShinySparkleAnim } from "#app/field/anims";
@@ -306,17 +306,17 @@ export class EggHatchPhase extends Phase {
     this.canSkip = false;
     this.hatched = true;
     if (this.evolutionBgm) {
-      SoundFade.fadeOut(globalScene, this.evolutionBgm, Utils.fixedInt(100));
+      SoundFade.fadeOut(globalScene, this.evolutionBgm, fixedInt(100));
     }
     for (let e = 0; e < 5; e++) {
-      globalScene.time.delayedCall(Utils.fixedInt(375 * e), () =>
+      globalScene.time.delayedCall(fixedInt(375 * e), () =>
         globalScene.playSound("se/egg_hatch", { volume: 1 - e * 0.2 }),
       );
     }
     this.eggLightraysOverlay.setVisible(true);
     this.eggLightraysOverlay.play("egg_lightrays");
     globalScene.tweens.add({
-      duration: Utils.fixedInt(125),
+      duration: fixedInt(125),
       targets: this.eggHatchOverlay,
       alpha: 1,
       ease: "Cubic.easeIn",
@@ -325,7 +325,7 @@ export class EggHatchPhase extends Phase {
         this.canSkip = true;
       },
     });
-    globalScene.time.delayedCall(Utils.fixedInt(1500), () => {
+    globalScene.time.delayedCall(fixedInt(1500), () => {
       this.canSkip = false;
       if (!this.skipped) {
         this.doReveal();
@@ -363,46 +363,43 @@ export class EggHatchPhase extends Phase {
     this.pokemonSprite.setPipelineData("shiny", this.pokemon.shiny);
     this.pokemonSprite.setPipelineData("variant", this.pokemon.variant);
     this.pokemonSprite.setVisible(true);
-    globalScene.time.delayedCall(Utils.fixedInt(250), () => {
+    globalScene.time.delayedCall(fixedInt(250), () => {
       this.eggsToHatchCount--;
       this.eggHatchHandler.eventTarget.dispatchEvent(new EggCountChangedEvent(this.eggsToHatchCount));
       this.pokemon.cry();
       if (isShiny) {
-        globalScene.time.delayedCall(Utils.fixedInt(500), () => {
+        globalScene.time.delayedCall(fixedInt(500), () => {
           doShinySparkleAnim(this.pokemonShinySparkle, this.pokemon.variant);
         });
       }
-      globalScene.time.delayedCall(
-        Utils.fixedInt(!this.skipped ? (!isShiny ? 1250 : 1750) : !isShiny ? 250 : 750),
-        () => {
-          this.infoContainer.show(this.pokemon, false, this.skipped ? 2 : 1);
+      globalScene.time.delayedCall(fixedInt(!this.skipped ? (!isShiny ? 1250 : 1750) : !isShiny ? 250 : 750), () => {
+        this.infoContainer.show(this.pokemon, false, this.skipped ? 2 : 1);
 
-          globalScene.playSoundWithoutBgm("evolution_fanfare");
+        globalScene.playSoundWithoutBgm("evolution_fanfare");
 
-          globalScene.ui.showText(
-            i18next.t("egg:hatchFromTheEgg", {
-              pokemonName: this.pokemon.species.getExpandedSpeciesName(),
-            }),
-            null,
-            () => {
-              globalScene.gameData.updateSpeciesDexIvs(this.pokemon.species.speciesId, this.pokemon.ivs);
-              globalScene.gameData.setPokemonCaught(this.pokemon, true, true).then(() => {
-                globalScene.gameData.setEggMoveUnlocked(this.pokemon.species, this.eggMoveIndex).then(value => {
-                  this.eggHatchData.setEggMoveUnlocked(value);
-                  globalScene.ui.showText("", 0);
-                  this.end();
-                });
+        globalScene.ui.showText(
+          i18next.t("egg:hatchFromTheEgg", {
+            pokemonName: this.pokemon.species.getExpandedSpeciesName(),
+          }),
+          null,
+          () => {
+            globalScene.gameData.updateSpeciesDexIvs(this.pokemon.species.speciesId, this.pokemon.ivs);
+            globalScene.gameData.setPokemonCaught(this.pokemon, true, true).then(() => {
+              globalScene.gameData.setEggMoveUnlocked(this.pokemon.species, this.eggMoveIndex).then(value => {
+                this.eggHatchData.setEggMoveUnlocked(value);
+                globalScene.ui.showText("", 0);
+                this.end();
               });
-            },
-            null,
-            true,
-            3000,
-          );
-        },
-      );
+            });
+          },
+          null,
+          true,
+          3000,
+        );
+      });
     });
     globalScene.tweens.add({
-      duration: Utils.fixedInt(this.skipped ? 500 : 3000),
+      duration: fixedInt(this.skipped ? 500 : 3000),
       targets: this.eggHatchOverlay,
       alpha: 0,
       ease: "Cubic.easeOut",
@@ -427,9 +424,9 @@ export class EggHatchPhase extends Phase {
   doSpray(intensity: number, offsetY?: number) {
     globalScene.tweens.addCounter({
       repeat: intensity,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
-        this.doSprayParticle(Utils.randInt(8), offsetY || 0);
+        this.doSprayParticle(randInt(8), offsetY || 0);
       },
     });
   }
@@ -448,12 +445,12 @@ export class EggHatchPhase extends Phase {
 
     let f = 0;
     let yOffset = 0;
-    const speed = 3 - Utils.randInt(8);
-    const amp = 24 + Utils.randInt(32);
+    const speed = 3 - randInt(8);
+    const amp = 24 + randInt(32);
 
     const particleTimer = globalScene.tweens.addCounter({
       repeat: -1,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         updateParticle();
       },
diff --git a/src/phases/encounter-phase.ts b/src/phases/encounter-phase.ts
index ad2bf689e38..9e5edf3e1d9 100644
--- a/src/phases/encounter-phase.ts
+++ b/src/phases/encounter-phase.ts
@@ -43,10 +43,10 @@ import { getNatureName } from "#app/data/nature";
 export class EncounterPhase extends BattlePhase {
   private loaded: boolean;
 
-  constructor(loaded?: boolean) {
+  constructor(loaded = false) {
     super();
 
-    this.loaded = !!loaded;
+    this.loaded = loaded;
   }
 
   start() {
diff --git a/src/phases/evolution-phase.ts b/src/phases/evolution-phase.ts
index bb283fa8139..203c7542eff 100644
--- a/src/phases/evolution-phase.ts
+++ b/src/phases/evolution-phase.ts
@@ -5,7 +5,7 @@ import { globalScene } from "#app/global-scene";
 import type { SpeciesFormEvolution } from "#app/data/balance/pokemon-evolutions";
 import { FusionSpeciesFormEvolution } from "#app/data/balance/pokemon-evolutions";
 import type EvolutionSceneHandler from "#app/ui/evolution-scene-handler";
-import * as Utils from "#app/utils";
+import { fixedInt, getFrameMs, randInt } from "#app/utils";
 import { Mode } from "#app/ui/ui";
 import { cos, sin } from "#app/field/anims";
 import type { PlayerPokemon } from "#app/field/pokemon";
@@ -332,9 +332,9 @@ export class EvolutionPhase extends Phase {
             () => this.end(),
             null,
             true,
-            Utils.fixedInt(4000),
+            fixedInt(4000),
           );
-          globalScene.time.delayedCall(Utils.fixedInt(4250), () => globalScene.playBgm());
+          globalScene.time.delayedCall(fixedInt(4250), () => globalScene.playBgm());
         });
       });
     };
@@ -392,7 +392,7 @@ export class EvolutionPhase extends Phase {
 
     globalScene.tweens.addCounter({
       repeat: 64,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         if (f < 64) {
           if (!(f & 7)) {
@@ -411,7 +411,7 @@ export class EvolutionPhase extends Phase {
 
     globalScene.tweens.addCounter({
       repeat: 96,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         if (f < 96) {
           if (f < 6) {
@@ -461,7 +461,7 @@ export class EvolutionPhase extends Phase {
 
     globalScene.tweens.addCounter({
       repeat: 48,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         if (!f) {
           for (let i = 0; i < 16; i++) {
@@ -482,14 +482,14 @@ export class EvolutionPhase extends Phase {
 
     globalScene.tweens.addCounter({
       repeat: 48,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         if (!f) {
           for (let i = 0; i < 8; i++) {
             this.doSprayParticle(i);
           }
         } else if (f < 50) {
-          this.doSprayParticle(Utils.randInt(8));
+          this.doSprayParticle(randInt(8));
         }
         f++;
       },
@@ -506,7 +506,7 @@ export class EvolutionPhase extends Phase {
 
     const particleTimer = globalScene.tweens.addCounter({
       repeat: -1,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         updateParticle();
       },
@@ -543,7 +543,7 @@ export class EvolutionPhase extends Phase {
 
     const particleTimer = globalScene.tweens.addCounter({
       repeat: -1,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         updateParticle();
       },
@@ -575,7 +575,7 @@ export class EvolutionPhase extends Phase {
 
     const particleTimer = globalScene.tweens.addCounter({
       repeat: -1,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         updateParticle();
       },
@@ -605,12 +605,12 @@ export class EvolutionPhase extends Phase {
 
     let f = 0;
     let yOffset = 0;
-    const speed = 3 - Utils.randInt(8);
-    const amp = 48 + Utils.randInt(64);
+    const speed = 3 - randInt(8);
+    const amp = 48 + randInt(64);
 
     const particleTimer = globalScene.tweens.addCounter({
       repeat: -1,
-      duration: Utils.getFrameMs(1),
+      duration: getFrameMs(1),
       onRepeat: () => {
         updateParticle();
       },
diff --git a/src/phases/exp-phase.ts b/src/phases/exp-phase.ts
index 092482d4c18..b7d62c92bcf 100644
--- a/src/phases/exp-phase.ts
+++ b/src/phases/exp-phase.ts
@@ -2,7 +2,7 @@ import { globalScene } from "#app/global-scene";
 import { getPokemonNameWithAffix } from "#app/messages";
 import { ExpBoosterModifier } from "#app/modifier/modifier";
 import i18next from "i18next";
-import * as Utils from "#app/utils";
+import { NumberHolder } from "#app/utils";
 import { PlayerPartyMemberPokemonPhase } from "./player-party-member-pokemon-phase";
 import { LevelUpPhase } from "./level-up-phase";
 
@@ -19,7 +19,7 @@ export class ExpPhase extends PlayerPartyMemberPokemonPhase {
     super.start();
 
     const pokemon = this.getPokemon();
-    const exp = new Utils.NumberHolder(this.expValue);
+    const exp = new NumberHolder(this.expValue);
     globalScene.applyModifiers(ExpBoosterModifier, true, exp);
     exp.value = Math.floor(exp.value);
     globalScene.ui.showText(
diff --git a/src/phases/form-change-phase.ts b/src/phases/form-change-phase.ts
index e0ec4e87600..bf94284b117 100644
--- a/src/phases/form-change-phase.ts
+++ b/src/phases/form-change-phase.ts
@@ -1,5 +1,5 @@
 import { globalScene } from "#app/global-scene";
-import * as Utils from "../utils";
+import { fixedInt } from "#app/utils";
 import { achvs } from "../system/achv";
 import type { SpeciesFormChange } from "../data/pokemon-forms";
 import { getSpeciesFormChangeMessage } from "../data/pokemon-forms";
@@ -9,7 +9,7 @@ import type PartyUiHandler from "../ui/party-ui-handler";
 import { getPokemonNameWithAffix } from "../messages";
 import { EndEvolutionPhase } from "./end-evolution-phase";
 import { EvolutionPhase } from "./evolution-phase";
-import { BattlerTagType } from "#app/enums/battler-tag-type";
+import { BattlerTagType } from "#enums/battler-tag-type";
 import { SpeciesFormKey } from "#enums/species-form-key";
 
 export class FormChangePhase extends EvolutionPhase {
@@ -151,9 +151,9 @@ export class FormChangePhase extends EvolutionPhase {
                                             () => this.end(),
                                             null,
                                             true,
-                                            Utils.fixedInt(delay),
+                                            fixedInt(delay),
                                           );
-                                          globalScene.time.delayedCall(Utils.fixedInt(delay + 250), () =>
+                                          globalScene.time.delayedCall(fixedInt(delay + 250), () =>
                                             globalScene.playBgm(),
                                           );
                                         });
diff --git a/src/phases/game-over-phase.ts b/src/phases/game-over-phase.ts
index f105b625cc8..1ccdc9c7106 100644
--- a/src/phases/game-over-phase.ts
+++ b/src/phases/game-over-phase.ts
@@ -20,7 +20,7 @@ import { UnlockPhase } from "#app/phases/unlock-phase";
 import { achvs, ChallengeAchv } from "#app/system/achv";
 import { Unlockables } from "#app/system/unlockables";
 import { Mode } from "#app/ui/ui";
-import * as Utils from "#app/utils";
+import { isLocal, isLocalServerConnected } from "#app/utils";
 import { PlayerGender } from "#enums/player-gender";
 import { TrainerType } from "#enums/trainer-type";
 import i18next from "i18next";
@@ -219,7 +219,7 @@ export class GameOverPhase extends BattlePhase {
     /* Added a local check to see if the game is running offline
       If Online, execute apiFetch as intended
       If Offline, execute offlineNewClear() only for victory, a localStorage implementation of newClear daily run checks */
-    if (!Utils.isLocal || Utils.isLocalServerConnected) {
+    if (!isLocal || isLocalServerConnected) {
       pokerogueApi.savedata.session
         .newclear({
           slot: globalScene.sessionSlotId,
diff --git a/src/phases/login-phase.ts b/src/phases/login-phase.ts
index 5cce6ca0298..846482ff726 100644
--- a/src/phases/login-phase.ts
+++ b/src/phases/login-phase.ts
@@ -5,26 +5,26 @@ import { Phase } from "#app/phase";
 import { handleTutorial, Tutorial } from "#app/tutorial";
 import { Mode } from "#app/ui/ui";
 import i18next, { t } from "i18next";
-import * as Utils from "#app/utils";
+import { getCookie, sessionIdKey, executeIf, removeCookie } from "#app/utils";
 import { SelectGenderPhase } from "./select-gender-phase";
 import { UnavailablePhase } from "./unavailable-phase";
 
 export class LoginPhase extends Phase {
   private showText: boolean;
 
-  constructor(showText?: boolean) {
+  constructor(showText = true) {
     super();
 
-    this.showText = showText === undefined || !!showText;
+    this.showText = showText;
   }
 
   start(): void {
     super.start();
 
-    const hasSession = !!Utils.getCookie(Utils.sessionIdKey);
+    const hasSession = !!getCookie(sessionIdKey);
 
     globalScene.ui.setMode(Mode.LOADING, { buttonActions: [] });
-    Utils.executeIf(bypassLogin || hasSession, updateUserInfo).then(response => {
+    executeIf(bypassLogin || hasSession, updateUserInfo).then(response => {
       const success = response ? response[0] : false;
       const statusCode = response ? response[1] : null;
       if (!success) {
@@ -38,7 +38,7 @@ export class LoginPhase extends Phase {
           const loadData = () => {
             updateUserInfo().then(success => {
               if (!success[0]) {
-                Utils.removeCookie(Utils.sessionIdKey);
+                removeCookie(sessionIdKey);
                 globalScene.reset(true, true);
                 return;
               }
@@ -60,7 +60,7 @@ export class LoginPhase extends Phase {
                       globalScene.ui.playSelect();
                       updateUserInfo().then(success => {
                         if (!success[0]) {
-                          Utils.removeCookie(Utils.sessionIdKey);
+                          removeCookie(sessionIdKey);
                           globalScene.reset(true, true);
                           return;
                         }
@@ -89,7 +89,7 @@ export class LoginPhase extends Phase {
             ],
           });
         } else if (statusCode === 401) {
-          Utils.removeCookie(Utils.sessionIdKey);
+          removeCookie(sessionIdKey);
           globalScene.reset(true, true);
         } else {
           globalScene.unshiftPhase(new UnavailablePhase());
diff --git a/src/phases/message-phase.ts b/src/phases/message-phase.ts
index cff7249fcfa..f6777579857 100644
--- a/src/phases/message-phase.ts
+++ b/src/phases/message-phase.ts
@@ -3,9 +3,9 @@ import { Phase } from "#app/phase";
 
 export class MessagePhase extends Phase {
   private text: string;
-  private callbackDelay: number | null;
-  private prompt: boolean | null;
-  private promptDelay: number | null;
+  private callbackDelay?: number | null;
+  private prompt?: boolean | null;
+  private promptDelay?: number | null;
   private speaker?: string;
 
   constructor(
@@ -18,9 +18,9 @@ export class MessagePhase extends Phase {
     super();
 
     this.text = text;
-    this.callbackDelay = callbackDelay!; // TODO: is this bang correct?
-    this.prompt = prompt!; // TODO: is this bang correct?
-    this.promptDelay = promptDelay!; // TODO: is this bang correct?
+    this.callbackDelay = callbackDelay;
+    this.prompt = prompt;
+    this.promptDelay = promptDelay;
     this.speaker = speaker;
   }
 
diff --git a/src/phases/money-reward-phase.ts b/src/phases/money-reward-phase.ts
index 56f46d25f77..ae8dc90616d 100644
--- a/src/phases/money-reward-phase.ts
+++ b/src/phases/money-reward-phase.ts
@@ -2,7 +2,7 @@ import { globalScene } from "#app/global-scene";
 import { ArenaTagType } from "#app/enums/arena-tag-type";
 import { MoneyMultiplierModifier } from "#app/modifier/modifier";
 import i18next from "i18next";
-import * as Utils from "#app/utils";
+import { NumberHolder } from "#app/utils";
 import { BattlePhase } from "./battle-phase";
 
 export class MoneyRewardPhase extends BattlePhase {
@@ -15,7 +15,7 @@ export class MoneyRewardPhase extends BattlePhase {
   }
 
   start() {
-    const moneyAmount = new Utils.NumberHolder(globalScene.getWaveMoneyAmount(this.moneyMultiplier));
+    const moneyAmount = new NumberHolder(globalScene.getWaveMoneyAmount(this.moneyMultiplier));
 
     globalScene.applyModifiers(MoneyMultiplierModifier, true, moneyAmount);
 
diff --git a/src/phases/move-anim-test-phase.ts b/src/phases/move-anim-test-phase.ts
deleted file mode 100644
index e8b7c0c8fa7..00000000000
--- a/src/phases/move-anim-test-phase.ts
+++ /dev/null
@@ -1,50 +0,0 @@
-import { globalScene } from "#app/global-scene";
-import { initMoveAnim, loadMoveAnimAssets, MoveAnim } from "#app/data/battle-anims";
-import { allMoves, SelfStatusMove } from "#app/data/moves/move";
-import { Moves } from "#app/enums/moves";
-import * as Utils from "#app/utils";
-import { BattlePhase } from "./battle-phase";
-
-export class MoveAnimTestPhase extends BattlePhase {
-  private moveQueue: Moves[];
-
-  constructor(moveQueue?: Moves[]) {
-    super();
-
-    this.moveQueue = moveQueue || Utils.getEnumValues(Moves).slice(1);
-  }
-
-  start() {
-    const moveQueue = this.moveQueue.slice(0);
-    this.playMoveAnim(moveQueue, true);
-  }
-
-  playMoveAnim(moveQueue: Moves[], player: boolean) {
-    const moveId = player ? moveQueue[0] : moveQueue.shift();
-    if (moveId === undefined) {
-      this.playMoveAnim(this.moveQueue.slice(0), true);
-      return;
-    }
-    if (player) {
-      console.log(Moves[moveId]);
-    }
-
-    initMoveAnim(moveId).then(() => {
-      loadMoveAnimAssets([moveId], true).then(() => {
-        const user = player ? globalScene.getPlayerPokemon()! : globalScene.getEnemyPokemon()!;
-        const target =
-          player !== allMoves[moveId] instanceof SelfStatusMove
-            ? globalScene.getEnemyPokemon()!
-            : globalScene.getPlayerPokemon()!;
-        new MoveAnim(moveId, user, target.getBattlerIndex()).play(allMoves[moveId].hitsSubstitute(user, target), () => {
-          // TODO: are the bangs correct here?
-          if (player) {
-            this.playMoveAnim(moveQueue, false);
-          } else {
-            this.playMoveAnim(moveQueue, true);
-          }
-        });
-      });
-    });
-  }
-}
diff --git a/src/phases/move-end-phase.ts b/src/phases/move-end-phase.ts
index f3a40ce69bd..53856956401 100644
--- a/src/phases/move-end-phase.ts
+++ b/src/phases/move-end-phase.ts
@@ -5,7 +5,7 @@ import type { BattlerIndex } from "#app/battle";
 
 export class MoveEndPhase extends PokemonPhase {
   private wasFollowUp: boolean;
-  constructor(battlerIndex: BattlerIndex, wasFollowUp: boolean = false) {
+  constructor(battlerIndex: BattlerIndex, wasFollowUp = false) {
     super(battlerIndex);
     this.wasFollowUp = wasFollowUp;
   }
diff --git a/src/phases/move-phase.ts b/src/phases/move-phase.ts
index 33e772eb2ea..82b73f681a0 100644
--- a/src/phases/move-phase.ts
+++ b/src/phases/move-phase.ts
@@ -227,7 +227,7 @@ export class MovePhase extends BattlePhase {
             (!this.pokemon.randSeedInt(4) || Overrides.STATUS_ACTIVATION_OVERRIDE === true) &&
             Overrides.STATUS_ACTIVATION_OVERRIDE !== false;
           break;
-        case StatusEffect.SLEEP:
+        case StatusEffect.SLEEP: {
           applyMoveAttrs(BypassSleepAttr, this.pokemon, null, this.move.getMove());
           const turnsRemaining = new NumberHolder(this.pokemon.status.sleepTurnsRemaining ?? 0);
           applyAbAttrs(
@@ -242,6 +242,7 @@ export class MovePhase extends BattlePhase {
           healed = this.pokemon.status.sleepTurnsRemaining <= 0;
           activated = !healed && !this.pokemon.getTag(BattlerTagType.BYPASS_SLEEP);
           break;
+        }
         case StatusEffect.FREEZE:
           healed =
             !!this.move
diff --git a/src/phases/mystery-encounter-phases.ts b/src/phases/mystery-encounter-phases.ts
index eb187617e69..f42290ff872 100644
--- a/src/phases/mystery-encounter-phases.ts
+++ b/src/phases/mystery-encounter-phases.ts
@@ -26,8 +26,7 @@ import { TrainerSlot } from "#enums/trainer-slot";
 import { IvScannerModifier } from "../modifier/modifier";
 import { Phase } from "../phase";
 import { Mode } from "../ui/ui";
-import * as Utils from "../utils";
-import { isNullOrUndefined } from "../utils";
+import { isNullOrUndefined, randSeedItem } from "#app/utils";
 
 /**
  * Will handle (in order):
@@ -387,7 +386,7 @@ export class MysteryEncounterBattlePhase extends Phase {
         const trainer = globalScene.currentBattle.trainer;
         let message: string;
         globalScene.executeWithSeedOffset(
-          () => (message = Utils.randSeedItem(encounterMessages)),
+          () => (message = randSeedItem(encounterMessages)),
           globalScene.currentBattle.mysteryEncounter?.getSeedOffset(),
         );
         message = message!; // tell TS compiler it's defined now
diff --git a/src/phases/new-biome-encounter-phase.ts b/src/phases/new-biome-encounter-phase.ts
index bb1fe54fe9f..3449a562c4a 100644
--- a/src/phases/new-biome-encounter-phase.ts
+++ b/src/phases/new-biome-encounter-phase.ts
@@ -4,10 +4,6 @@ import { getRandomWeatherType } from "#app/data/weather";
 import { NextEncounterPhase } from "./next-encounter-phase";
 
 export class NewBiomeEncounterPhase extends NextEncounterPhase {
-  constructor() {
-    super();
-  }
-
   doEncounter(): void {
     globalScene.playBgm(undefined, true);
 
diff --git a/src/phases/next-encounter-phase.ts b/src/phases/next-encounter-phase.ts
index e53f775f083..e5e61312c3b 100644
--- a/src/phases/next-encounter-phase.ts
+++ b/src/phases/next-encounter-phase.ts
@@ -2,10 +2,6 @@ import { globalScene } from "#app/global-scene";
 import { EncounterPhase } from "./encounter-phase";
 
 export class NextEncounterPhase extends EncounterPhase {
-  constructor() {
-    super();
-  }
-
   start() {
     super.start();
   }
diff --git a/src/phases/party-heal-phase.ts b/src/phases/party-heal-phase.ts
index a9b24309e24..137af9f3a2d 100644
--- a/src/phases/party-heal-phase.ts
+++ b/src/phases/party-heal-phase.ts
@@ -1,5 +1,5 @@
 import { globalScene } from "#app/global-scene";
-import * as Utils from "#app/utils";
+import { fixedInt } from "#app/utils";
 import { BattlePhase } from "./battle-phase";
 
 export class PartyHealPhase extends BattlePhase {
@@ -28,7 +28,7 @@ export class PartyHealPhase extends BattlePhase {
         pokemon.updateInfo(true);
       }
       const healSong = globalScene.playSoundWithoutBgm("heal");
-      globalScene.time.delayedCall(Utils.fixedInt(healSong.totalDuration * 1000), () => {
+      globalScene.time.delayedCall(fixedInt(healSong.totalDuration * 1000), () => {
         healSong.destroy();
         if (this.resumeBgm && bgmPlaying) {
           globalScene.playBgm();
diff --git a/src/phases/pokemon-anim-phase.ts b/src/phases/pokemon-anim-phase.ts
index b9c91508b5a..f0693a52aaa 100644
--- a/src/phases/pokemon-anim-phase.ts
+++ b/src/phases/pokemon-anim-phase.ts
@@ -8,18 +8,18 @@ import { Species } from "#enums/species";
 
 export class PokemonAnimPhase extends BattlePhase {
   /** The type of animation to play in this phase */
-  private key: PokemonAnimType;
+  protected key: PokemonAnimType;
   /** The Pokemon to which this animation applies */
-  private pokemon: Pokemon;
+  protected pokemon: Pokemon;
   /** Any other field sprites affected by this animation */
-  private fieldAssets: Phaser.GameObjects.Sprite[];
+  protected fieldAssets: Phaser.GameObjects.Sprite[];
 
-  constructor(key: PokemonAnimType, pokemon: Pokemon, fieldAssets?: Phaser.GameObjects.Sprite[]) {
+  constructor(key: PokemonAnimType, pokemon: Pokemon, fieldAssets: Phaser.GameObjects.Sprite[] = []) {
     super();
 
     this.key = key;
     this.pokemon = pokemon;
-    this.fieldAssets = fieldAssets ?? [];
+    this.fieldAssets = fieldAssets;
   }
 
   start(): void {
diff --git a/src/phases/pokemon-heal-phase.ts b/src/phases/pokemon-heal-phase.ts
index ecfe99389eb..651c625b23a 100644
--- a/src/phases/pokemon-heal-phase.ts
+++ b/src/phases/pokemon-heal-phase.ts
@@ -8,7 +8,7 @@ import { getPokemonNameWithAffix } from "#app/messages";
 import { HealingBoosterModifier } from "#app/modifier/modifier";
 import { HealAchv } from "#app/system/achv";
 import i18next from "i18next";
-import * as Utils from "#app/utils";
+import { NumberHolder } from "#app/utils";
 import { CommonAnimPhase } from "./common-anim-phase";
 import { BattlerTagType } from "#app/enums/battler-tag-type";
 import type { HealBlockTag } from "#app/data/battler-tags";
@@ -72,11 +72,11 @@ export class PokemonHealPhase extends CommonAnimPhase {
       return super.end();
     }
     if (healOrDamage) {
-      const hpRestoreMultiplier = new Utils.NumberHolder(1);
+      const hpRestoreMultiplier = new NumberHolder(1);
       if (!this.revive) {
         globalScene.applyModifiers(HealingBoosterModifier, this.player, hpRestoreMultiplier);
       }
-      const healAmount = new Utils.NumberHolder(Math.floor(this.hpHealed * hpRestoreMultiplier.value));
+      const healAmount = new NumberHolder(Math.floor(this.hpHealed * hpRestoreMultiplier.value));
       if (healAmount.value < 0) {
         pokemon.damageAndUpdate(healAmount.value * -1, { result: HitResult.INDIRECT });
         healAmount.value = 0;
diff --git a/src/phases/pokemon-phase.ts b/src/phases/pokemon-phase.ts
index 3ca5f09f953..8c30512cdc4 100644
--- a/src/phases/pokemon-phase.ts
+++ b/src/phases/pokemon-phase.ts
@@ -11,11 +11,14 @@ export abstract class PokemonPhase extends FieldPhase {
   constructor(battlerIndex?: BattlerIndex | number) {
     super();
 
-    if (battlerIndex === undefined) {
-      battlerIndex = globalScene
+    battlerIndex =
+      battlerIndex ??
+      globalScene
         .getField()
-        .find(p => p?.isActive())!
-        .getBattlerIndex(); // TODO: is the bang correct here?
+        .find(p => p?.isActive())! // TODO: is the bang correct here?
+        .getBattlerIndex();
+    if (battlerIndex === undefined) {
+      console.warn("There are no Pokemon on the field!"); // TODO: figure out a suitable fallback behavior
     }
 
     this.battlerIndex = battlerIndex;
diff --git a/src/phases/post-game-over-phase.ts b/src/phases/post-game-over-phase.ts
index f86ec8496e0..753251e992f 100644
--- a/src/phases/post-game-over-phase.ts
+++ b/src/phases/post-game-over-phase.ts
@@ -4,12 +4,12 @@ import type { EndCardPhase } from "./end-card-phase";
 import { TitlePhase } from "./title-phase";
 
 export class PostGameOverPhase extends Phase {
-  private endCardPhase: EndCardPhase | null;
+  private endCardPhase?: EndCardPhase;
 
   constructor(endCardPhase?: EndCardPhase) {
     super();
 
-    this.endCardPhase = endCardPhase!; // TODO: is this bang correct?
+    this.endCardPhase = endCardPhase;
   }
 
   start() {
diff --git a/src/phases/post-turn-status-effect-phase.ts b/src/phases/post-turn-status-effect-phase.ts
index f6341666e7e..619ef22d01e 100644
--- a/src/phases/post-turn-status-effect-phase.ts
+++ b/src/phases/post-turn-status-effect-phase.ts
@@ -13,7 +13,7 @@ import { getStatusEffectActivationText } from "#app/data/status-effect";
 import { BattleSpec } from "#app/enums/battle-spec";
 import { StatusEffect } from "#app/enums/status-effect";
 import { getPokemonNameWithAffix } from "#app/messages";
-import * as Utils from "#app/utils";
+import { BooleanHolder, NumberHolder } from "#app/utils";
 import { PokemonPhase } from "./pokemon-phase";
 
 export class PostTurnStatusEffectPhase extends PokemonPhase {
@@ -26,7 +26,7 @@ export class PostTurnStatusEffectPhase extends PokemonPhase {
     const pokemon = this.getPokemon();
     if (pokemon?.isActive(true) && pokemon.status && pokemon.status.isPostTurn() && !pokemon.switchOutStatus) {
       pokemon.status.incrementTurn();
-      const cancelled = new Utils.BooleanHolder(false);
+      const cancelled = new BooleanHolder(false);
       applyAbAttrs(BlockNonDirectDamageAbAttr, pokemon, cancelled);
       applyAbAttrs(BlockStatusDamageAbAttr, pokemon, cancelled);
 
@@ -34,7 +34,7 @@ export class PostTurnStatusEffectPhase extends PokemonPhase {
         globalScene.queueMessage(
           getStatusEffectActivationText(pokemon.status.effect, getPokemonNameWithAffix(pokemon)),
         );
-        const damage = new Utils.NumberHolder(0);
+        const damage = new NumberHolder(0);
         switch (pokemon.status.effect) {
           case StatusEffect.POISON:
             damage.value = Math.max(pokemon.getMaxHp() >> 3, 1);
diff --git a/src/phases/reload-session-phase.ts b/src/phases/reload-session-phase.ts
index 3a4a4e0e3a5..a7ac0002b03 100644
--- a/src/phases/reload-session-phase.ts
+++ b/src/phases/reload-session-phase.ts
@@ -1,15 +1,15 @@
 import { globalScene } from "#app/global-scene";
 import { Phase } from "#app/phase";
 import { Mode } from "#app/ui/ui";
-import * as Utils from "#app/utils";
+import { fixedInt } from "#app/utils";
 
 export class ReloadSessionPhase extends Phase {
-  private systemDataStr: string | null;
+  private systemDataStr?: string;
 
   constructor(systemDataStr?: string) {
     super();
 
-    this.systemDataStr = systemDataStr ?? null;
+    this.systemDataStr = systemDataStr;
   }
 
   start(): void {
@@ -18,7 +18,7 @@ export class ReloadSessionPhase extends Phase {
     let delayElapsed = false;
     let loaded = false;
 
-    globalScene.time.delayedCall(Utils.fixedInt(1500), () => {
+    globalScene.time.delayedCall(fixedInt(1500), () => {
       if (loaded) {
         this.end();
       } else {
diff --git a/src/phases/scan-ivs-phase.ts b/src/phases/scan-ivs-phase.ts
index 2a2d68591ca..aaeeb7f84f8 100644
--- a/src/phases/scan-ivs-phase.ts
+++ b/src/phases/scan-ivs-phase.ts
@@ -8,6 +8,7 @@ import i18next from "i18next";
 import { PokemonPhase } from "./pokemon-phase";
 
 export class ScanIvsPhase extends PokemonPhase {
+  // biome-ignore lint/complexity/noUselessConstructor: This changes `battlerIndex` to be required
   constructor(battlerIndex: BattlerIndex) {
     super(battlerIndex);
   }
@@ -24,7 +25,8 @@ export class ScanIvsPhase extends PokemonPhase {
     const uiTheme = globalScene.uiTheme; // Assuming uiTheme is accessible
     for (let e = 0; e < enemyField.length; e++) {
       enemyIvs = enemyField[e].ivs;
-      const currentIvs = globalScene.gameData.dexData[enemyField[e].species.getRootSpeciesId()].ivs; // we are using getRootSpeciesId() here because we want to check against the baby form, not the mid form if it exists
+      // we are using getRootSpeciesId() here because we want to check against the baby form, not the mid form if it exists
+      const currentIvs = globalScene.gameData.dexData[enemyField[e].species.getRootSpeciesId()].ivs;
       statsContainer = enemyField[e].getBattleInfo().getStatsValueContainer().list as Phaser.GameObjects.Sprite[];
       statsContainerLabels = statsContainer.filter(m => m.name.indexOf("icon_stat_label") >= 0);
       for (let s = 0; s < statsContainerLabels.length; s++) {
diff --git a/src/phases/select-biome-phase.ts b/src/phases/select-biome-phase.ts
index 6a11967832a..2d67cb87405 100644
--- a/src/phases/select-biome-phase.ts
+++ b/src/phases/select-biome-phase.ts
@@ -5,15 +5,11 @@ import { MoneyInterestModifier, MapModifier } from "#app/modifier/modifier";
 import type { OptionSelectItem } from "#app/ui/abstact-option-select-ui-handler";
 import { Mode } from "#app/ui/ui";
 import { BattlePhase } from "./battle-phase";
-import * as Utils from "#app/utils";
+import { randSeedInt } from "#app/utils";
 import { PartyHealPhase } from "./party-heal-phase";
 import { SwitchBiomePhase } from "./switch-biome-phase";
 
 export class SelectBiomePhase extends BattlePhase {
-  constructor() {
-    super();
-  }
-
   start() {
     super.start();
 
@@ -40,7 +36,7 @@ export class SelectBiomePhase extends BattlePhase {
       let biomes: Biome[] = [];
       globalScene.executeWithSeedOffset(() => {
         biomes = (biomeLinks[currentBiome] as (Biome | [Biome, number])[])
-          .filter(b => !Array.isArray(b) || !Utils.randSeedInt(b[1]))
+          .filter(b => !Array.isArray(b) || !randSeedInt(b[1]))
           .map(b => (!Array.isArray(b) ? b : b[0]));
       }, globalScene.currentBattle.waveIndex);
       if (biomes.length > 1 && globalScene.findModifier(m => m instanceof MapModifier)) {
@@ -51,7 +47,7 @@ export class SelectBiomePhase extends BattlePhase {
               ? [biomeLinks[currentBiome] as Biome]
               : (biomeLinks[currentBiome] as (Biome | [Biome, number])[])
           )
-            .filter((b, _i) => !Array.isArray(b) || !Utils.randSeedInt(b[1]))
+            .filter(b => !Array.isArray(b) || !randSeedInt(b[1]))
             .map(b => (Array.isArray(b) ? b[0] : b));
         }, globalScene.currentBattle.waveIndex);
         const biomeSelectItems = biomeChoices.map(b => {
@@ -70,7 +66,7 @@ export class SelectBiomePhase extends BattlePhase {
           delay: 1000,
         });
       } else {
-        setNextBiome(biomes[Utils.randSeedInt(biomes.length)]);
+        setNextBiome(biomes[randSeedInt(biomes.length)]);
       }
     } else if (biomeLinks.hasOwnProperty(currentBiome)) {
       setNextBiome(biomeLinks[currentBiome] as Biome);
diff --git a/src/phases/select-challenge-phase.ts b/src/phases/select-challenge-phase.ts
index 2a6797d3556..5e6f20f93ee 100644
--- a/src/phases/select-challenge-phase.ts
+++ b/src/phases/select-challenge-phase.ts
@@ -3,10 +3,6 @@ import { Phase } from "#app/phase";
 import { Mode } from "#app/ui/ui";
 
 export class SelectChallengePhase extends Phase {
-  constructor() {
-    super();
-  }
-
   start() {
     super.start();
 
diff --git a/src/phases/select-gender-phase.ts b/src/phases/select-gender-phase.ts
index 1c86536de53..4da60b38aa1 100644
--- a/src/phases/select-gender-phase.ts
+++ b/src/phases/select-gender-phase.ts
@@ -6,10 +6,6 @@ import { Mode } from "#app/ui/ui";
 import i18next from "i18next";
 
 export class SelectGenderPhase extends Phase {
-  constructor() {
-    super();
-  }
-
   start(): void {
     super.start();
 
diff --git a/src/phases/select-modifier-phase.ts b/src/phases/select-modifier-phase.ts
index 11d448876d3..27ab7e374a2 100644
--- a/src/phases/select-modifier-phase.ts
+++ b/src/phases/select-modifier-phase.ts
@@ -26,7 +26,6 @@ import { SHOP_OPTIONS_ROW_LIMIT } from "#app/ui/modifier-select-ui-handler";
 import PartyUiHandler, { PartyUiMode, PartyOption } from "#app/ui/party-ui-handler";
 import { Mode } from "#app/ui/ui";
 import i18next from "i18next";
-import * as Utils from "#app/utils";
 import { BattlePhase } from "./battle-phase";
 import Overrides from "#app/overrides";
 import type { CustomModifierSettings } from "#app/modifier/modifier-type";
@@ -67,7 +66,7 @@ export class SelectModifierPhase extends BattlePhase {
     if (!this.isCopy) {
       regenerateModifierPoolThresholds(party, this.getPoolType(), this.rerollCount);
     }
-    const modifierCount = new Utils.NumberHolder(3);
+    const modifierCount = new NumberHolder(3);
     if (this.isPlayer()) {
       globalScene.applyModifiers(ExtraModifierModifier, true, modifierCount);
       globalScene.applyModifiers(TempExtraModifierModifier, true, modifierCount);
diff --git a/src/phases/select-starter-phase.ts b/src/phases/select-starter-phase.ts
index b3ebe6731c9..c6ded6be7af 100644
--- a/src/phases/select-starter-phase.ts
+++ b/src/phases/select-starter-phase.ts
@@ -15,10 +15,6 @@ import SoundFade from "phaser3-rex-plugins/plugins/soundfade";
 import * as Utils from "../utils";
 
 export class SelectStarterPhase extends Phase {
-  constructor() {
-    super();
-  }
-
   start() {
     super.start();
 
diff --git a/src/phases/select-target-phase.ts b/src/phases/select-target-phase.ts
index 2042d0a3fcf..035eaff41fa 100644
--- a/src/phases/select-target-phase.ts
+++ b/src/phases/select-target-phase.ts
@@ -8,6 +8,7 @@ import i18next from "#app/plugins/i18n";
 import { allMoves } from "#app/data/moves/move";
 
 export class SelectTargetPhase extends PokemonPhase {
+  // biome-ignore lint/complexity/noUselessConstructor: This makes `fieldIndex` required
   constructor(fieldIndex: number) {
     super(fieldIndex);
   }
diff --git a/src/phases/shiny-sparkle-phase.ts b/src/phases/shiny-sparkle-phase.ts
index 2540d98fb79..87a7db29cf6 100644
--- a/src/phases/shiny-sparkle-phase.ts
+++ b/src/phases/shiny-sparkle-phase.ts
@@ -3,6 +3,7 @@ import type { BattlerIndex } from "#app/battle";
 import { PokemonPhase } from "./pokemon-phase";
 
 export class ShinySparklePhase extends PokemonPhase {
+  // biome-ignore lint/complexity/noUselessConstructor: This makes `battlerIndex` required
   constructor(battlerIndex: BattlerIndex) {
     super(battlerIndex);
   }
diff --git a/src/phases/show-party-exp-bar-phase.ts b/src/phases/show-party-exp-bar-phase.ts
index 568b8b615c8..139f4efcc49 100644
--- a/src/phases/show-party-exp-bar-phase.ts
+++ b/src/phases/show-party-exp-bar-phase.ts
@@ -2,7 +2,7 @@ import { globalScene } from "#app/global-scene";
 import { ExpGainsSpeed } from "#app/enums/exp-gains-speed";
 import { ExpNotification } from "#app/enums/exp-notification";
 import { ExpBoosterModifier } from "#app/modifier/modifier";
-import * as Utils from "#app/utils";
+import { NumberHolder } from "#app/utils";
 import { HidePartyExpBarPhase } from "./hide-party-exp-bar-phase";
 import { LevelUpPhase } from "./level-up-phase";
 import { PlayerPartyMemberPokemonPhase } from "./player-party-member-pokemon-phase";
@@ -20,7 +20,7 @@ export class ShowPartyExpBarPhase extends PlayerPartyMemberPokemonPhase {
     super.start();
 
     const pokemon = this.getPokemon();
-    const exp = new Utils.NumberHolder(this.expValue);
+    const exp = new NumberHolder(this.expValue);
     globalScene.applyModifiers(ExpBoosterModifier, true, exp);
     exp.value = Math.floor(exp.value);
 
diff --git a/src/phases/show-trainer-phase.ts b/src/phases/show-trainer-phase.ts
index 740c11f5c5d..b6c1e345c70 100644
--- a/src/phases/show-trainer-phase.ts
+++ b/src/phases/show-trainer-phase.ts
@@ -3,10 +3,6 @@ import { PlayerGender } from "#app/enums/player-gender";
 import { BattlePhase } from "./battle-phase";
 
 export class ShowTrainerPhase extends BattlePhase {
-  constructor() {
-    super();
-  }
-
   start() {
     super.start();
 
diff --git a/src/phases/summon-missing-phase.ts b/src/phases/summon-missing-phase.ts
index 32bc7495dce..a692455ce47 100644
--- a/src/phases/summon-missing-phase.ts
+++ b/src/phases/summon-missing-phase.ts
@@ -4,10 +4,6 @@ import { SummonPhase } from "./summon-phase";
 import { globalScene } from "#app/global-scene";
 
 export class SummonMissingPhase extends SummonPhase {
-  constructor(fieldIndex: number) {
-    super(fieldIndex);
-  }
-
   preSummon(): void {
     globalScene.ui.showText(
       i18next.t("battle:sendOutPokemon", {
diff --git a/src/phases/switch-summon-phase.ts b/src/phases/switch-summon-phase.ts
index 16868bf9bc0..e0903ada275 100644
--- a/src/phases/switch-summon-phase.ts
+++ b/src/phases/switch-summon-phase.ts
@@ -23,11 +23,11 @@ export class SwitchSummonPhase extends SummonPhase {
 
   /**
    * Constructor for creating a new SwitchSummonPhase
-   * @param switchType the type of switch behavior
-   * @param fieldIndex integer representing position on the battle field
-   * @param slotIndex integer for the index of pokemon (in party of 6) to switch into
-   * @param doReturn boolean whether to render "comeback" dialogue
-   * @param player boolean if the switch is from the player
+   * @param switchType - The type of switch behavior
+   * @param fieldIndex - Position on the battle field
+   * @param slotIndex - The index of pokemon (in party of 6) to switch into
+   * @param doReturn - Whether to render "comeback" dialogue
+   * @param player - (Optional) `true` if the switch is from the player
    */
   constructor(switchType: SwitchType, fieldIndex: number, slotIndex: number, doReturn: boolean, player?: boolean) {
     super(fieldIndex, player !== undefined ? player : true);
diff --git a/src/phases/test-message-phase.ts b/src/phases/test-message-phase.ts
deleted file mode 100644
index d5e74efd490..00000000000
--- a/src/phases/test-message-phase.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-import { MessagePhase } from "./message-phase";
-
-export class TestMessagePhase extends MessagePhase {
-  constructor(message: string) {
-    super(message, null, true);
-  }
-}
diff --git a/src/phases/title-phase.ts b/src/phases/title-phase.ts
index dc455a0a62a..108366d4774 100644
--- a/src/phases/title-phase.ts
+++ b/src/phases/title-phase.ts
@@ -18,7 +18,7 @@ import { vouchers } from "#app/system/voucher";
 import type { OptionSelectConfig, OptionSelectItem } from "#app/ui/abstact-option-select-ui-handler";
 import { SaveSlotUiMode } from "#app/ui/save-slot-select-ui-handler";
 import { Mode } from "#app/ui/ui";
-import * as Utils from "#app/utils";
+import { isLocal, isLocalServerConnected, isNullOrUndefined } from "#app/utils";
 import i18next from "i18next";
 import { CheckSwitchPhase } from "./check-switch-phase";
 import { EncounterPhase } from "./encounter-phase";
@@ -29,16 +29,10 @@ import { globalScene } from "#app/global-scene";
 import Overrides from "#app/overrides";
 
 export class TitlePhase extends Phase {
-  private loaded: boolean;
+  private loaded = false;
   private lastSessionData: SessionSaveData;
   public gameMode: GameModes;
 
-  constructor() {
-    super();
-
-    this.loaded = false;
-  }
-
   start(): void {
     super.start();
 
@@ -282,7 +276,7 @@ export class TitlePhase extends Phase {
       };
 
       // If Online, calls seed fetch from db to generate daily run. If Offline, generates a daily run based on current date.
-      if (!Utils.isLocal || Utils.isLocalServerConnected) {
+      if (!isLocal || isLocalServerConnected) {
         fetchDailyRunSeed()
           .then(seed => {
             if (seed) {
@@ -296,7 +290,7 @@ export class TitlePhase extends Phase {
           });
       } else {
         let seed: string = btoa(new Date().toISOString().substring(0, 10));
-        if (!Utils.isNullOrUndefined(Overrides.DAILY_RUN_SEED_OVERRIDE)) {
+        if (!isNullOrUndefined(Overrides.DAILY_RUN_SEED_OVERRIDE)) {
           seed = Overrides.DAILY_RUN_SEED_OVERRIDE;
         }
         generateDaily(seed);
diff --git a/src/phases/trainer-message-test-phase.ts b/src/phases/trainer-message-test-phase.ts
deleted file mode 100644
index 23c2c86361c..00000000000
--- a/src/phases/trainer-message-test-phase.ts
+++ /dev/null
@@ -1,47 +0,0 @@
-import { globalScene } from "#app/global-scene";
-import { trainerConfigs } from "#app/data/trainers/trainer-config";
-import type { TrainerType } from "#app/enums/trainer-type";
-import { BattlePhase } from "./battle-phase";
-import { TestMessagePhase } from "./test-message-phase";
-
-export class TrainerMessageTestPhase extends BattlePhase {
-  private trainerTypes: TrainerType[];
-
-  constructor(...trainerTypes: TrainerType[]) {
-    super();
-
-    this.trainerTypes = trainerTypes;
-  }
-
-  start() {
-    super.start();
-
-    const testMessages: string[] = [];
-
-    for (const t of Object.keys(trainerConfigs)) {
-      const type = Number.parseInt(t);
-      if (this.trainerTypes.length && !this.trainerTypes.find(tt => tt === (type as TrainerType))) {
-        continue;
-      }
-      const config = trainerConfigs[type];
-      [
-        config.encounterMessages,
-        config.femaleEncounterMessages,
-        config.victoryMessages,
-        config.femaleVictoryMessages,
-        config.defeatMessages,
-        config.femaleDefeatMessages,
-      ].map(messages => {
-        if (messages?.length) {
-          testMessages.push(...messages);
-        }
-      });
-    }
-
-    for (const message of testMessages) {
-      globalScene.pushPhase(new TestMessagePhase(message));
-    }
-
-    this.end();
-  }
-}
diff --git a/src/phases/trainer-victory-phase.ts b/src/phases/trainer-victory-phase.ts
index a024885121f..637ddea8b56 100644
--- a/src/phases/trainer-victory-phase.ts
+++ b/src/phases/trainer-victory-phase.ts
@@ -3,7 +3,7 @@ import { TrainerType } from "#app/enums/trainer-type";
 import { modifierTypes } from "#app/modifier/modifier-type";
 import { vouchers } from "#app/system/voucher";
 import i18next from "i18next";
-import * as Utils from "#app/utils";
+import { randSeedItem } from "#app/utils";
 import { BattlePhase } from "./battle-phase";
 import { ModifierRewardPhase } from "./modifier-reward-phase";
 import { MoneyRewardPhase } from "./money-reward-phase";
@@ -14,10 +14,6 @@ import { achvs } from "#app/system/achv";
 import { timedEventManager } from "#app/global-event-manager";
 
 export class TrainerVictoryPhase extends BattlePhase {
-  constructor() {
-    super();
-  }
-
   start() {
     globalScene.disableMenu = true;
 
@@ -82,7 +78,7 @@ export class TrainerVictoryPhase extends BattlePhase {
         const victoryMessages = globalScene.currentBattle.trainer?.getVictoryMessages()!; // TODO: is this bang correct?
         let message: string;
         globalScene.executeWithSeedOffset(
-          () => (message = Utils.randSeedItem(victoryMessages)),
+          () => (message = randSeedItem(victoryMessages)),
           globalScene.currentBattle.waveIndex,
         );
         message = message!; // tell TS compiler it's defined now
diff --git a/src/phases/turn-end-phase.ts b/src/phases/turn-end-phase.ts
index ddfc0955508..9b84ea05e58 100644
--- a/src/phases/turn-end-phase.ts
+++ b/src/phases/turn-end-phase.ts
@@ -18,10 +18,6 @@ import { PokemonHealPhase } from "./pokemon-heal-phase";
 import { globalScene } from "#app/global-scene";
 
 export class TurnEndPhase extends FieldPhase {
-  constructor() {
-    super();
-  }
-
   start() {
     super.start();
 
diff --git a/src/phases/turn-init-phase.ts b/src/phases/turn-init-phase.ts
index 3104b65eb3f..0c110024af7 100644
--- a/src/phases/turn-init-phase.ts
+++ b/src/phases/turn-init-phase.ts
@@ -15,10 +15,6 @@ import { TurnStartPhase } from "./turn-start-phase";
 import { globalScene } from "#app/global-scene";
 
 export class TurnInitPhase extends FieldPhase {
-  constructor() {
-    super();
-  }
-
   start() {
     super.start();
 
diff --git a/src/phases/turn-start-phase.ts b/src/phases/turn-start-phase.ts
index 34dd7df3e89..d5b4160fe1b 100644
--- a/src/phases/turn-start-phase.ts
+++ b/src/phases/turn-start-phase.ts
@@ -6,7 +6,7 @@ import type Pokemon from "#app/field/pokemon";
 import { PokemonMove } from "#app/field/pokemon";
 import { BypassSpeedChanceModifier } from "#app/modifier/modifier";
 import { Command } from "#app/ui/command-ui-handler";
-import * as Utils from "#app/utils";
+import { randSeedShuffle, BooleanHolder } from "#app/utils";
 import { AttemptCapturePhase } from "./attempt-capture-phase";
 import { AttemptRunPhase } from "./attempt-run-phase";
 import { BerryPhase } from "./berry-phase";
@@ -24,10 +24,6 @@ import { globalScene } from "#app/global-scene";
 import { TeraPhase } from "./tera-phase";
 
 export class TurnStartPhase extends FieldPhase {
-  constructor() {
-    super();
-  }
-
   /**
    * This orders the active Pokemon on the field by speed into an BattlerIndex array and returns that array.
    * It also checks for Trick Room and reverses the array if it is present.
@@ -43,14 +39,14 @@ export class TurnStartPhase extends FieldPhase {
     // was varying based on how long since you last reloaded
     globalScene.executeWithSeedOffset(
       () => {
-        orderedTargets = Utils.randSeedShuffle(orderedTargets);
+        orderedTargets = randSeedShuffle(orderedTargets);
       },
       globalScene.currentBattle.turn,
       globalScene.waveSeed,
     );
 
     // Next, a check for Trick Room is applied to determine sort order.
-    const speedReversed = new Utils.BooleanHolder(false);
+    const speedReversed = new BooleanHolder(false);
     globalScene.arena.applyTags(TrickRoomTag, false, speedReversed);
 
     // Adjust the sort function based on whether Trick Room is active.
@@ -80,8 +76,8 @@ export class TurnStartPhase extends FieldPhase {
       .getField(true)
       .filter(p => p.summonData)
       .map(p => {
-        const bypassSpeed = new Utils.BooleanHolder(false);
-        const canCheckHeldItems = new Utils.BooleanHolder(true);
+        const bypassSpeed = new BooleanHolder(false);
+        const canCheckHeldItems = new BooleanHolder(true);
         applyAbAttrs(BypassSpeedChanceAbAttr, p, null, false, bypassSpeed);
         applyAbAttrs(PreventBypassSpeedChanceAbAttr, p, null, false, bypassSpeed, canCheckHeldItems);
         if (canCheckHeldItems.value) {
diff --git a/src/phases/unavailable-phase.ts b/src/phases/unavailable-phase.ts
index c0b5d4224c5..33042739971 100644
--- a/src/phases/unavailable-phase.ts
+++ b/src/phases/unavailable-phase.ts
@@ -4,10 +4,6 @@ import { Mode } from "#app/ui/ui";
 import { LoginPhase } from "./login-phase";
 
 export class UnavailablePhase extends Phase {
-  constructor() {
-    super();
-  }
-
   start(): void {
     globalScene.ui.setMode(Mode.UNAVAILABLE, () => {
       globalScene.unshiftPhase(new LoginPhase(true));
diff --git a/src/phases/weather-effect-phase.ts b/src/phases/weather-effect-phase.ts
index d7a1f193029..5284c9fba85 100644
--- a/src/phases/weather-effect-phase.ts
+++ b/src/phases/weather-effect-phase.ts
@@ -15,7 +15,7 @@ import { BattlerTagType } from "#app/enums/battler-tag-type";
 import { WeatherType } from "#app/enums/weather-type";
 import type Pokemon from "#app/field/pokemon";
 import { HitResult } from "#app/field/pokemon";
-import * as Utils from "#app/utils";
+import { BooleanHolder, toDmgValue } from "#app/utils";
 import { CommonAnimPhase } from "./common-anim-phase";
 
 export class WeatherEffectPhase extends CommonAnimPhase {
@@ -35,14 +35,13 @@ export class WeatherEffectPhase extends CommonAnimPhase {
     this.weather = globalScene?.arena?.weather;
 
     if (!this.weather) {
-      this.end();
-      return;
+      return this.end();
     }
 
     this.setAnimation(CommonAnim.SUNNY + (this.weather.weatherType - 1));
 
     if (this.weather.isDamaging()) {
-      const cancelled = new Utils.BooleanHolder(false);
+      const cancelled = new BooleanHolder(false);
 
       this.executeForAll((pokemon: Pokemon) =>
         applyPreWeatherEffectAbAttrs(SuppressWeatherEffectAbAttr, pokemon, this.weather, cancelled),
@@ -50,7 +49,7 @@ export class WeatherEffectPhase extends CommonAnimPhase {
 
       if (!cancelled.value) {
         const inflictDamage = (pokemon: Pokemon) => {
-          const cancelled = new Utils.BooleanHolder(false);
+          const cancelled = new BooleanHolder(false);
 
           applyPreWeatherEffectAbAttrs(PreWeatherDamageAbAttr, pokemon, this.weather, cancelled);
           applyAbAttrs(BlockNonDirectDamageAbAttr, pokemon, cancelled);
@@ -63,9 +62,9 @@ export class WeatherEffectPhase extends CommonAnimPhase {
             return;
           }
 
-          const damage = Utils.toDmgValue(pokemon.getMaxHp() / 16);
+          const damage = toDmgValue(pokemon.getMaxHp() / 16);
 
-          globalScene.queueMessage(getWeatherDamageMessage(this.weather?.weatherType!, pokemon)!); // TODO: are those bangs correct?
+          globalScene.queueMessage(getWeatherDamageMessage(this.weather!.weatherType, pokemon) ?? "");
           pokemon.damageAndUpdate(damage, { result: HitResult.INDIRECT, ignoreSegments: true });
         };