diff --git a/src/battle.ts b/src/battle.ts
index 601cbeb9cb6..56186b2570d 100644
--- a/src/battle.ts
+++ b/src/battle.ts
@@ -93,10 +93,8 @@ export default class Battle {
 
     private initBattleSpec(): void {
         let spec = BattleSpec.DEFAULT;
-        if (this.gameMode.isClassic) {
-            if (this.waveIndex === 200)
-                spec = BattleSpec.FINAL_BOSS;
-        }
+        if (this.gameMode.isWaveFinal(this.waveIndex) && this.gameMode.isClassic)
+            spec = BattleSpec.FINAL_BOSS;
         this.battleSpec = spec;
     }
 
@@ -105,7 +103,7 @@ export default class Battle {
         let baseLevel = 1 + levelWaveIndex / 2 + Math.pow(levelWaveIndex / 25, 2);
         const bossMultiplier = 1.2;
 
-        if (!(this.waveIndex % 10)) {
+        if (this.gameMode.isBoss(this.waveIndex)) {
             const ret = Math.floor(baseLevel * bossMultiplier);
             if (this.battleSpec === BattleSpec.FINAL_BOSS || !(this.waveIndex % 250))
                 return Math.ceil(ret / 25) * 25;
diff --git a/src/game-mode.ts b/src/game-mode.ts
index 888ae3b3c84..bedcf429757 100644
--- a/src/game-mode.ts
+++ b/src/game-mode.ts
@@ -147,8 +147,14 @@ export class GameMode implements GameModeConfig {
     return null;
   }
 
-  isWaveFinal(waveIndex: integer): boolean {
-    switch (this.modeId) {
+  /**
+   * Checks if wave provided is the final for current or specified game mode
+   * @param waveIndex 
+   * @param modeId game mode
+   * @returns if the current wave is final for classic or daily OR a minor boss in endless
+   */
+  isWaveFinal(waveIndex: integer, modeId: GameModes = this.modeId): boolean {
+    switch (modeId) {
       case GameModes.CLASSIC:
         return waveIndex === 200;
       case GameModes.ENDLESS:
@@ -159,6 +165,45 @@ export class GameMode implements GameModeConfig {
     }
   }
 
+    /**
+     * Every 10 waves is a boss battle
+     * @returns true if waveIndex is a multiple of 10
+     */
+    isBoss(waveIndex: integer): boolean {
+      return waveIndex % 10 === 0;
+    }
+
+    /**
+     * Every 50 waves of an Endless mode is a boss
+     * At this time it is paradox pokemon
+     * @returns true if waveIndex is a multiple of 50 in Endless
+     */
+    isEndlessBoss(waveIndex: integer): boolean {
+      return waveIndex % 50 &&
+        (this.modeId === GameModes.ENDLESS || this.modeId === GameModes.SPLICED_ENDLESS);
+    }
+
+    /**
+     * Every 250 waves of an Endless mode is a minor boss
+     * At this time it is Eternatus
+     * @returns true if waveIndex is a multiple of 250 in Endless
+     */
+    isEndlessMinorBoss(waveIndex: integer): boolean {
+      return waveIndex % 250 === 0 && 
+        (this.modeId === GameModes.ENDLESS || this.modeId === GameModes.SPLICED_ENDLESS);
+    }
+
+    /**
+     * Every 1000 waves of an Endless mode is a major boss
+     * At this time it is Eternamax Eternatus
+     * @returns true if waveIndex is a multiple of 1000 in Endless
+     */
+    isEndlessMajorBoss(waveIndex: integer): boolean {
+      return waveIndex % 1000 === 0 && 
+        (this.modeId === GameModes.ENDLESS || this.modeId === GameModes.SPLICED_ENDLESS);
+    }
+
+
   getClearScoreBonus(): integer {
     switch (this.modeId) {
       case GameModes.CLASSIC: