diff --git a/src/battle-scene.ts b/src/battle-scene.ts
index 6143ecd7d7a..8c575dfe50b 100644
--- a/src/battle-scene.ts
+++ b/src/battle-scene.ts
@@ -64,6 +64,7 @@ import { ShopCursorTarget } from "#enums/shop-cursor-target";
 import { SpeciesId } from "#enums/species-id";
 import { StatusEffect } from "#enums/status-effect";
 import { TextStyle } from "#enums/text-style";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerItemId } from "#enums/trainer-item-id";
 import type { TrainerSlot } from "#enums/trainer-slot";
 import { TrainerType } from "#enums/trainer-type";
@@ -77,11 +78,11 @@ import { EnemyPokemon, PlayerPokemon } from "#field/pokemon";
 import { PokemonSpriteSparkleHandler } from "#field/pokemon-sprite-sparkle-handler";
 import { Trainer } from "#field/trainer";
 import { applyHeldItems } from "#items/all-held-items";
-import { type ApplyTrainerItemsParams, applyTrainerItems } from "#items/apply-trainer-items";
+import { applyTrainerItems } from "#items/all-trainer-items";
 import type { HeldItemConfiguration } from "#items/held-item-data-types";
 import { assignEnemyHeldItemsForWave, assignItemsFromConfiguration } from "#items/held-item-pool";
 import type { MatchExact, Reward } from "#items/reward";
-import { type EnemyAttackStatusEffectChanceTrainerItem, TrainerItemEffect } from "#items/trainer-item";
+import type { EnemyAttackStatusEffectChanceTrainerItem } from "#items/trainer-item";
 import {
   isTrainerItemPool,
   isTrainerItemSpecs,
@@ -89,6 +90,7 @@ import {
   type TrainerItemSaveData,
 } from "#items/trainer-item-data-types";
 import { TrainerItemManager } from "#items/trainer-item-manager";
+import type { TrainerItemEffectParamMap } from "#items/trainer-item-parameter";
 import { getNewTrainerItemFromPool } from "#items/trainer-item-pool";
 import { MysteryEncounter } from "#mystery-encounters/mystery-encounter";
 import { MysteryEncounterSaveData } from "#mystery-encounters/mystery-encounter-save-data";
@@ -2608,7 +2610,7 @@ export class BattleScene extends SceneBase {
     return Math.floor(moneyValue / 10) * 10;
   }
 
-  applyPlayerItems<T extends TrainerItemEffect>(effect: T, params: ApplyTrainerItemsParams[T]) {
+  applyPlayerItems<T extends TrainerItemEffect>(effect: T, params: TrainerItemEffectParamMap[T]) {
     applyTrainerItems(effect, this.trainerItems, params);
   }
 
diff --git a/src/battle.ts b/src/battle.ts
index 709e7a23164..fd447e9cbf8 100644
--- a/src/battle.ts
+++ b/src/battle.ts
@@ -12,12 +12,12 @@ import type { MysteryEncounterType } from "#enums/mystery-encounter-type";
 import type { PokeballType } from "#enums/pokeball";
 import { SpeciesFormKey } from "#enums/species-form-key";
 import { SpeciesId } from "#enums/species-id";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerType } from "#enums/trainer-type";
 import { TrainerVariant } from "#enums/trainer-variant";
 import type { EnemyPokemon, PlayerPokemon, Pokemon } from "#field/pokemon";
 import { Trainer } from "#field/trainer";
 import type { CustomRewardSettings } from "#items/reward-pool-utils";
-import { TrainerItemEffect } from "#items/trainer-item";
 import type { MysteryEncounter } from "#mystery-encounters/mystery-encounter";
 import i18next from "#plugins/i18n";
 import { MusicPreference } from "#system/settings";
diff --git a/src/data/balance/pokemon-evolutions.ts b/src/data/balance/pokemon-evolutions.ts
index 54938fe4d17..82dc4390fb9 100644
--- a/src/data/balance/pokemon-evolutions.ts
+++ b/src/data/balance/pokemon-evolutions.ts
@@ -159,7 +159,7 @@ export class SpeciesEvolutionCondition {
         case EvoCondKey.SPECIES_CAUGHT:
           return i18next.t("pokemonEvolutions:caught", {species: getPokemonSpecies(cond.speciesCaught).name});
         case EvoCondKey.HELD_ITEM:
-          return i18next.t(`pokemonEvolutions:heldItem.${toCamelCase(cond.itemKey)}`);
+          return i18next.t(`pokemonEvolutions:heldItem.${toCamelCase(allHeldItems[cond.itemKey].name)}`);
       }
     }).filter(s => !isNullOrUndefined(s)); // Filter out stringless conditions
     return this.desc;
diff --git a/src/data/moves/move.ts b/src/data/moves/move.ts
index 5d1f6e6b570..aba5c672138 100644
--- a/src/data/moves/move.ts
+++ b/src/data/moves/move.ts
@@ -71,7 +71,6 @@ import type { EnemyPokemon, Pokemon } from "#field/pokemon";
 import { applyHeldItems } from "#items/all-held-items";
 import { BerryHeldItem, berryTypeToHeldItem } from "#items/berry";
 import { HeldItemEffect } from "#enums/held-item-effect";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { applyMoveAttrs } from "#moves/apply-attrs";
 import { invalidAssistMoves, invalidCopycatMoves, invalidMetronomeMoves, invalidMirrorMoveMoves, invalidSketchMoves, invalidSleepTalkMoves } from "#moves/invalid-moves";
 import { frenzyMissFunc, getMoveTargets } from "#moves/move-utils";
@@ -90,6 +89,7 @@ import { toCamelCase, toTitleCase } from "#utils/strings";
 import i18next from "i18next";
 import { applyChallenges } from "#utils/challenge-utils";
 import type { AbstractConstructor } from "#types/type-helpers";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 
 /**
  * A function used to conditionally determine execution of a given {@linkcode MoveAttr}.
diff --git a/src/data/mystery-encounters/encounters/global-trade-system-encounter.ts b/src/data/mystery-encounters/encounters/global-trade-system-encounter.ts
index 3aedfab1e1f..09256ea4003 100644
--- a/src/data/mystery-encounters/encounters/global-trade-system-encounter.ts
+++ b/src/data/mystery-encounters/encounters/global-trade-system-encounter.ts
@@ -15,6 +15,7 @@ import type { PokeballType } from "#enums/pokeball";
 import { RewardPoolType } from "#enums/reward-pool-type";
 import { RarityTier } from "#enums/reward-tier";
 import { SpeciesId } from "#enums/species-id";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerSlot } from "#enums/trainer-slot";
 import { TrainerType } from "#enums/trainer-type";
 import { doShinySparkleAnim } from "#field/anims";
@@ -24,7 +25,6 @@ import { getHeldItemTier } from "#items/held-item-default-tiers";
 import type { RewardOption } from "#items/reward";
 import { generatePlayerRewardOptions, generateRewardPoolWeights, getRewardPoolForType } from "#items/reward-pool-utils";
 import { isTmReward } from "#items/reward-utils";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { PokemonMove } from "#moves/pokemon-move";
 import { getEncounterText, showEncounterText } from "#mystery-encounters/encounter-dialogue-utils";
 import {
diff --git a/src/data/mystery-encounters/encounters/safari-zone-encounter.ts b/src/data/mystery-encounters/encounters/safari-zone-encounter.ts
index 0528f334182..a654a5fd487 100644
--- a/src/data/mystery-encounters/encounters/safari-zone-encounter.ts
+++ b/src/data/mystery-encounters/encounters/safari-zone-encounter.ts
@@ -8,10 +8,10 @@ import { MysteryEncounterTier } from "#enums/mystery-encounter-tier";
 import { MysteryEncounterType } from "#enums/mystery-encounter-type";
 import { PlayerGender } from "#enums/player-gender";
 import { PokeballType } from "#enums/pokeball";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerItemId } from "#enums/trainer-item-id";
 import { TrainerSlot } from "#enums/trainer-slot";
 import type { EnemyPokemon } from "#field/pokemon";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { getEncounterText, showEncounterText } from "#mystery-encounters/encounter-dialogue-utils";
 import {
   initSubsequentOptionSelect,
diff --git a/src/data/mystery-encounters/encounters/weird-dream-encounter.ts b/src/data/mystery-encounters/encounters/weird-dream-encounter.ts
index 88ffba42000..e0d8845aabe 100644
--- a/src/data/mystery-encounters/encounters/weird-dream-encounter.ts
+++ b/src/data/mystery-encounters/encounters/weird-dream-encounter.ts
@@ -16,10 +16,10 @@ import { RewardId } from "#enums/reward-id";
 import { RarityTier } from "#enums/reward-tier";
 import { SpeciesId } from "#enums/species-id";
 import { StatusEffect } from "#enums/status-effect";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerType } from "#enums/trainer-type";
 import type { PlayerPokemon, Pokemon } from "#field/pokemon";
 import type { HeldItemConfiguration } from "#items/held-item-data-types";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { PokemonMove } from "#moves/pokemon-move";
 import { showEncounterText } from "#mystery-encounters/encounter-dialogue-utils";
 import type { EnemyPartyConfig, EnemyPokemonConfig } from "#mystery-encounters/encounter-phase-utils";
diff --git a/src/data/pokeball.ts b/src/data/pokeball.ts
index 967928f4d43..5611fddb254 100644
--- a/src/data/pokeball.ts
+++ b/src/data/pokeball.ts
@@ -1,6 +1,6 @@
 import { globalScene } from "#app/global-scene";
 import { PokeballType } from "#enums/pokeball";
-import { TrainerItemEffect } from "#items/trainer-item";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { NumberHolder } from "#utils/common";
 import i18next from "i18next";
 
diff --git a/src/enums/trainer-item-effect.ts b/src/enums/trainer-item-effect.ts
new file mode 100644
index 00000000000..3669de16382
--- /dev/null
+++ b/src/enums/trainer-item-effect.ts
@@ -0,0 +1,28 @@
+export const TrainerItemEffect = {
+  LEVEL_INCREMENT_BOOSTER: 1,
+  PRESERVE_BERRY: 2,
+  HEALING_BOOSTER: 3,
+  EXP_BOOSTER: 4,
+  MONEY_MULTIPLIER: 5,
+  HIDDEN_ABILITY_CHANCE_BOOSTER: 6,
+  SHINY_RATE_BOOSTER: 7,
+  CRITICAL_CATCH_CHANCE_BOOSTER: 8,
+  EXTRA_REWARD: 9,
+
+  HEAL_SHOP_COST: 10,
+  DOUBLE_BATTLE_CHANCE_BOOSTER: 11,
+
+  TEMP_STAT_STAGE_BOOSTER: 12,
+  TEMP_ACCURACY_BOOSTER: 13,
+  TEMP_CRIT_BOOSTER: 14,
+
+  ENEMY_DAMAGE_BOOSTER: 15,
+  ENEMY_DAMAGE_REDUCER: 16,
+  ENEMY_HEAL: 17,
+  ENEMY_ATTACK_STATUS_CHANCE: 18,
+  ENEMY_STATUS_HEAL_CHANCE: 19,
+  ENEMY_ENDURE_CHANCE: 20,
+  ENEMY_FUSED_CHANCE: 21,
+} as const;
+
+export type TrainerItemEffect = (typeof TrainerItemEffect)[keyof typeof TrainerItemEffect];
diff --git a/src/field/pokemon.ts b/src/field/pokemon.ts
index e8360b13acc..76edc853086 100644
--- a/src/field/pokemon.ts
+++ b/src/field/pokemon.ts
@@ -106,6 +106,7 @@ import {
 } from "#enums/stat";
 import { StatusEffect } from "#enums/status-effect";
 import { SwitchType } from "#enums/switch-type";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import type { TrainerSlot } from "#enums/trainer-slot";
 import { UiMode } from "#enums/ui-mode";
 import { WeatherType } from "#enums/weather-type";
@@ -114,7 +115,6 @@ import { applyHeldItems } from "#items/all-held-items";
 import type { HeldItemConfiguration } from "#items/held-item-data-types";
 import { HeldItemManager } from "#items/held-item-manager";
 import { assignItemsFromConfiguration } from "#items/held-item-pool";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { applyMoveAttrs } from "#moves/apply-attrs";
 import type { Move } from "#moves/move";
 import { getMoveTargets } from "#moves/move-utils";
diff --git a/src/items/all-trainer-items.ts b/src/items/all-trainer-items.ts
index 487bd3224d0..23fe6a4b089 100644
--- a/src/items/all-trainer-items.ts
+++ b/src/items/all-trainer-items.ts
@@ -1,6 +1,7 @@
 import { allTrainerItems } from "#data/data-lists";
 import { Stat, type TempBattleStat } from "#enums/stat";
 import { StatusEffect } from "#enums/status-effect";
+import type { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerItemId } from "#enums/trainer-item-id";
 import {
   CriticalCatchChanceBoosterTrainerItem,
@@ -27,6 +28,8 @@ import {
   TrainerItem,
   tempStatToTrainerItem,
 } from "#items/trainer-item";
+import type { TrainerItemManager } from "./trainer-item-manager";
+import type { TrainerItemEffectParamMap } from "./trainer-item-parameter";
 
 export function initTrainerItems() {
   allTrainerItems[TrainerItemId.MAP] = new TrainerItem(TrainerItemId.MAP, 1);
@@ -112,3 +115,17 @@ export function initTrainerItems() {
     10,
   );
 }
+
+export function applyTrainerItems<T extends TrainerItemEffect>(
+  effect: T,
+  manager: TrainerItemManager,
+  params: TrainerItemEffectParamMap[T],
+) {
+  if (manager) {
+    for (const item of Object.keys(manager.trainerItems)) {
+      if (allTrainerItems[item].effects.includes(effect)) {
+        allTrainerItems[item].apply(manager, params);
+      }
+    }
+  }
+}
diff --git a/src/items/held-item.ts b/src/items/held-item.ts
index ab79aa54c2c..ebd70a6d580 100644
--- a/src/items/held-item.ts
+++ b/src/items/held-item.ts
@@ -174,5 +174,6 @@ export abstract class ConsumableHeldItem<T extends EffectTuple> extends HeldItem
 }
 
 /** Abstract class for all items that are purely cosmetic.
- * Currently coincides with the {@linkcode HeldItemBase} class. */
+ * Currently coincides with the {@linkcode HeldItemBase} class.
+ * Might become concrete later on if we want cosmetic items without a subclass. */
 export abstract class CosmeticHeldItem extends HeldItemBase {}
diff --git a/src/items/held-items/berry.ts b/src/items/held-items/berry.ts
index 1eaa9825301..52d46a71725 100644
--- a/src/items/held-items/berry.ts
+++ b/src/items/held-items/berry.ts
@@ -3,10 +3,10 @@ import { getBerryEffectDescription, getBerryEffectFunc, getBerryName, getBerryPr
 import { BerryType } from "#enums/berry-type";
 import { HeldItemEffect } from "#enums/held-item-effect";
 import { HeldItemId } from "#enums/held-item-id";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { BerryUsedEvent } from "#events/battle-scene";
 import { ConsumableHeldItem } from "#items/held-item";
 import type { BerryParams } from "#items/held-item-parameter";
-import { TrainerItemEffect } from "#items/trainer-item";
 import type { ObjectValues } from "#types/type-helpers";
 import { BooleanHolder } from "#utils/common";
 
diff --git a/src/items/held-items/damage-money-reward.ts b/src/items/held-items/damage-money-reward.ts
index 13a6d44682c..602d73e43f0 100644
--- a/src/items/held-items/damage-money-reward.ts
+++ b/src/items/held-items/damage-money-reward.ts
@@ -1,8 +1,8 @@
 import { globalScene } from "#app/global-scene";
 import { HeldItemEffect } from "#enums/held-item-effect";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { HeldItem } from "#items/held-item";
 import type { DamageMoneyRewardParams } from "#items/held-item-parameter";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { NumberHolder } from "#utils/common";
 
 export class DamageMoneyRewardHeldItem extends HeldItem<[typeof HeldItemEffect.DAMAGE_MONEY_REWARD]> {
diff --git a/src/items/reward.ts b/src/items/reward.ts
index f52806b04b9..0f549217524 100644
--- a/src/items/reward.ts
+++ b/src/items/reward.ts
@@ -25,6 +25,7 @@ import { SpeciesFormKey } from "#enums/species-form-key";
 import { SpeciesId } from "#enums/species-id";
 import type { PermanentStat, TempBattleStat } from "#enums/stat";
 import { Stat, TEMP_BATTLE_STATS } from "#enums/stat";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerItemId } from "#enums/trainer-item-id";
 import type { PlayerPokemon, Pokemon } from "#field/pokemon";
 import { attackTypeToHeldItem } from "#items/attack-type-booster";
@@ -32,7 +33,7 @@ import { permanentStatToHeldItem, statBoostItems } from "#items/base-stat-booste
 import { berryTypeToHeldItem } from "#items/berry";
 import { getNewAttackTypeBoosterHeldItem, getNewBerryHeldItem, getNewVitaminHeldItem } from "#items/held-item-pool";
 import type { SpeciesStatBoosterItemId, SpeciesStatBoostHeldItem } from "#items/stat-booster";
-import { TrainerItemEffect, tempStatToTrainerItem } from "#items/trainer-item";
+import { tempStatToTrainerItem } from "#items/trainer-item";
 import type { PokemonMove } from "#moves/pokemon-move";
 import { getVoucherTypeIcon, getVoucherTypeName, type VoucherType } from "#system/voucher";
 import type { Exact } from "#types/type-helpers";
diff --git a/src/items/apply-trainer-items.ts b/src/items/trainer-item-parameter.ts
similarity index 65%
rename from src/items/apply-trainer-items.ts
rename to src/items/trainer-item-parameter.ts
index 7abeee18df9..bf5b1f8ba29 100644
--- a/src/items/apply-trainer-items.ts
+++ b/src/items/trainer-item-parameter.ts
@@ -1,14 +1,25 @@
-import { allTrainerItems } from "#data/data-lists";
-import {
-  type BooleanHolderParams,
-  type NumberHolderParams,
-  type PokemonParams,
-  type PreserveBerryParams,
-  TrainerItemEffect,
-} from "#items/trainer-item";
-import type { TrainerItemManager } from "#items/trainer-item-manager";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
+import type { Pokemon } from "#field/pokemon";
+import type { BooleanHolder, NumberHolder } from "#utils/common";
 
-export type ApplyTrainerItemsParams = {
+export interface NumberHolderParams {
+  numberHolder: NumberHolder;
+}
+
+export interface BooleanHolderParams {
+  booleanHolder: BooleanHolder;
+}
+
+export interface PokemonParams {
+  pokemon: Pokemon;
+}
+
+export interface PreserveBerryParams {
+  pokemon: Pokemon;
+  doPreserve: BooleanHolder;
+}
+
+export type TrainerItemEffectParamMap = {
   [TrainerItemEffect.LEVEL_INCREMENT_BOOSTER]: NumberHolderParams;
   [TrainerItemEffect.PRESERVE_BERRY]: PreserveBerryParams;
   [TrainerItemEffect.HEALING_BOOSTER]: NumberHolderParams;
@@ -31,17 +42,3 @@ export type ApplyTrainerItemsParams = {
   [TrainerItemEffect.ENEMY_ENDURE_CHANCE]: PokemonParams;
   [TrainerItemEffect.ENEMY_FUSED_CHANCE]: BooleanHolderParams;
 };
-
-export function applyTrainerItems<T extends TrainerItemEffect>(
-  effect: T,
-  manager: TrainerItemManager,
-  params: ApplyTrainerItemsParams[T],
-) {
-  if (manager) {
-    for (const item of Object.keys(manager.trainerItems)) {
-      if (allTrainerItems[item].effects.includes(effect)) {
-        allTrainerItems[item].apply(manager, params);
-      }
-    }
-  }
-}
diff --git a/src/items/trainer-item.ts b/src/items/trainer-item.ts
index f19f370594f..d247361e4fb 100644
--- a/src/items/trainer-item.ts
+++ b/src/items/trainer-item.ts
@@ -5,53 +5,18 @@ import { BattlerTagType } from "#enums/battler-tag-type";
 import { getStatKey, Stat, type TempBattleStat } from "#enums/stat";
 import { StatusEffect } from "#enums/status-effect";
 import { TextStyle } from "#enums/text-style";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerItemId, TrainerItemNames } from "#enums/trainer-item-id";
-import type { Pokemon } from "#field/pokemon";
 import type { TrainerItemManager } from "#items/trainer-item-manager";
 import { addTextObject } from "#ui/text";
-import { type BooleanHolder, hslToHex, type NumberHolder, randSeedFloat, toDmgValue } from "#utils/common";
+import { hslToHex, randSeedFloat, toDmgValue } from "#utils/common";
 import i18next from "i18next";
-
-export const TrainerItemEffect = {
-  LEVEL_INCREMENT_BOOSTER: 1,
-  PRESERVE_BERRY: 2,
-  HEALING_BOOSTER: 3,
-  EXP_BOOSTER: 4,
-  MONEY_MULTIPLIER: 5,
-  HIDDEN_ABILITY_CHANCE_BOOSTER: 6,
-  SHINY_RATE_BOOSTER: 7,
-  CRITICAL_CATCH_CHANCE_BOOSTER: 8,
-  EXTRA_REWARD: 9,
-
-  HEAL_SHOP_COST: 10,
-  DOUBLE_BATTLE_CHANCE_BOOSTER: 11,
-
-  TEMP_STAT_STAGE_BOOSTER: 12,
-  TEMP_ACCURACY_BOOSTER: 13,
-  TEMP_CRIT_BOOSTER: 14,
-
-  ENEMY_DAMAGE_BOOSTER: 15,
-  ENEMY_DAMAGE_REDUCER: 16,
-  ENEMY_HEAL: 17,
-  ENEMY_ATTACK_STATUS_CHANCE: 18,
-  ENEMY_STATUS_HEAL_CHANCE: 19,
-  ENEMY_ENDURE_CHANCE: 20,
-  ENEMY_FUSED_CHANCE: 21,
-} as const;
-
-export type TrainerItemEffect = (typeof TrainerItemEffect)[keyof typeof TrainerItemEffect];
-
-export interface NumberHolderParams {
-  numberHolder: NumberHolder;
-}
-
-export interface BooleanHolderParams {
-  booleanHolder: BooleanHolder;
-}
-
-export interface PokemonParams {
-  pokemon: Pokemon;
-}
+import type {
+  BooleanHolderParams,
+  NumberHolderParams,
+  PokemonParams,
+  PreserveBerryParams,
+} from "./trainer-item-parameter";
 
 export class TrainerItem {
   //  public pokemonId: number;
@@ -130,11 +95,6 @@ export class LevelIncrementBoosterTrainerItem extends TrainerItem {
 }
 
 // Berry Pouch
-export interface PreserveBerryParams {
-  pokemon: Pokemon;
-  doPreserve: BooleanHolder;
-}
-
 export class PreserveBerryTrainerItem extends TrainerItem {
   public effects: TrainerItemEffect[] = [TrainerItemEffect.PRESERVE_BERRY];
 
@@ -491,7 +451,7 @@ export class EnemyAttackStatusEffectChanceTrainerItem extends TrainerItem {
     const chance = this.getChance();
 
     if (randSeedFloat() <= chance * stack) {
-      return enemyPokemon.trySetStatus(this.effect, true);
+      return enemyPokemon.trySetStatus(this.effect);
     }
 
     return false;
diff --git a/src/phases/berry-phase.ts b/src/phases/berry-phase.ts
index fd8783a9e28..62f3ae40594 100644
--- a/src/phases/berry-phase.ts
+++ b/src/phases/berry-phase.ts
@@ -35,7 +35,10 @@ export class BerryPhase extends FieldPhase {
    */
   eatBerries(pokemon: Pokemon): void {
     const hasUsableBerry = pokemon.getHeldItems().some(m => {
-      return isItemInCategory(m, HeldItemCategoryId.BERRY) && (allHeldItems[m] as BerryHeldItem).shouldApply(pokemon);
+      return (
+        isItemInCategory(m, HeldItemCategoryId.BERRY) &&
+        (allHeldItems[m] as BerryHeldItem).shouldApply(HeldItemEffect.BERRY, { pokemon: pokemon })
+      );
     });
 
     if (!hasUsableBerry) {
diff --git a/src/phases/exp-phase.ts b/src/phases/exp-phase.ts
index 4ab58bdbf9c..f400d7e278e 100644
--- a/src/phases/exp-phase.ts
+++ b/src/phases/exp-phase.ts
@@ -1,6 +1,6 @@
 import { globalScene } from "#app/global-scene";
 import { getPokemonNameWithAffix } from "#app/messages";
-import { TrainerItemEffect } from "#items/trainer-item";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { PlayerPartyMemberPokemonPhase } from "#phases/player-party-member-pokemon-phase";
 import { NumberHolder } from "#utils/common";
 import i18next from "i18next";
diff --git a/src/phases/money-reward-phase.ts b/src/phases/money-reward-phase.ts
index 1b6b4ded6b1..9fa00489580 100644
--- a/src/phases/money-reward-phase.ts
+++ b/src/phases/money-reward-phase.ts
@@ -1,6 +1,6 @@
 import { globalScene } from "#app/global-scene";
 import { ArenaTagType } from "#enums/arena-tag-type";
-import { TrainerItemEffect } from "#items/trainer-item";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { BattlePhase } from "#phases/battle-phase";
 import { NumberHolder } from "#utils/common";
 import i18next from "i18next";
diff --git a/src/phases/move-effect-phase.ts b/src/phases/move-effect-phase.ts
index 04a17ae4ad6..0bac0dae684 100644
--- a/src/phases/move-effect-phase.ts
+++ b/src/phases/move-effect-phase.ts
@@ -22,9 +22,9 @@ import { MoveResult } from "#enums/move-result";
 import { MoveTarget } from "#enums/move-target";
 import { isReflected, MoveUseMode } from "#enums/move-use-mode";
 import { PokemonType } from "#enums/pokemon-type";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import type { Pokemon } from "#field/pokemon";
 import { applyHeldItems } from "#items/all-held-items";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { applyFilteredMoveAttrs, applyMoveAttrs } from "#moves/apply-attrs";
 import type { Move, MoveAttr } from "#moves/move";
 import { getMoveTargets, isFieldTargeted } from "#moves/move-utils";
diff --git a/src/phases/pokemon-heal-phase.ts b/src/phases/pokemon-heal-phase.ts
index c89e1c081e7..2d1f8edc294 100644
--- a/src/phases/pokemon-heal-phase.ts
+++ b/src/phases/pokemon-heal-phase.ts
@@ -7,7 +7,7 @@ import { BattlerTagType } from "#enums/battler-tag-type";
 import { HitResult } from "#enums/hit-result";
 import { CommonAnim } from "#enums/move-anims-common";
 import { StatusEffect } from "#enums/status-effect";
-import { TrainerItemEffect } from "#items/trainer-item";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { CommonAnimPhase } from "#phases/common-anim-phase";
 import { HealAchv } from "#system/achv";
 import { NumberHolder } from "#utils/common";
diff --git a/src/phases/select-reward-phase.ts b/src/phases/select-reward-phase.ts
index ad0cce1c4f8..be752fb4539 100644
--- a/src/phases/select-reward-phase.ts
+++ b/src/phases/select-reward-phase.ts
@@ -3,6 +3,7 @@ import Overrides from "#app/overrides";
 import type { MoveId } from "#enums/move-id";
 import { RewardPoolType } from "#enums/reward-pool-type";
 import type { RarityTier } from "#enums/reward-tier";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { UiMode } from "#enums/ui-mode";
 import type {
   PokemonMoveRecallRewardParams,
@@ -19,7 +20,6 @@ import {
   getRewardPoolForType,
 } from "#items/reward-pool-utils";
 import { getPlayerShopRewardOptionsForWave, isMoveReward, isRememberMoveReward, isTmReward } from "#items/reward-utils";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { BattlePhase } from "#phases/battle-phase";
 import { PartyOption, PartyUiHandler, PartyUiMode, type PokemonMoveSelectFilter } from "#ui/party-ui-handler";
 import { type RewardSelectUiHandler, SHOP_OPTIONS_ROW_LIMIT } from "#ui/reward-select-ui-handler";
diff --git a/src/phases/show-party-exp-bar-phase.ts b/src/phases/show-party-exp-bar-phase.ts
index 4599c4b37cc..6d80b09c103 100644
--- a/src/phases/show-party-exp-bar-phase.ts
+++ b/src/phases/show-party-exp-bar-phase.ts
@@ -1,7 +1,7 @@
 import { globalScene } from "#app/global-scene";
 import { ExpGainsSpeed } from "#enums/exp-gains-speed";
 import { ExpNotification } from "#enums/exp-notification";
-import { TrainerItemEffect } from "#items/trainer-item";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { PlayerPartyMemberPokemonPhase } from "#phases/player-party-member-pokemon-phase";
 import { NumberHolder } from "#utils/common";
 
diff --git a/src/phases/stat-stage-change-phase.ts b/src/phases/stat-stage-change-phase.ts
index 8156149628a..b5ffb07366d 100644
--- a/src/phases/stat-stage-change-phase.ts
+++ b/src/phases/stat-stage-change-phase.ts
@@ -233,7 +233,7 @@ export class StatStageChangePhase extends PokemonPhase {
       );
       if (!existingPhase?.is("StatStageChangePhase")) {
         // Apply White Herb if needed
-        applyHeldItems(HeldItemEffect.RESET_NEGATIVE_STAT_STAGE, { pokemon: pokemon, isPlayer: this.player });
+        applyHeldItems(HeldItemEffect.RESET_NEGATIVE_STAT_STAGE, { pokemon: pokemon });
       }
 
       pokemon.updateInfo();
diff --git a/src/phases/turn-end-phase.ts b/src/phases/turn-end-phase.ts
index 2a42c560433..efa0a4dbd81 100644
--- a/src/phases/turn-end-phase.ts
+++ b/src/phases/turn-end-phase.ts
@@ -4,11 +4,11 @@ import { getPokemonNameWithAffix } from "#app/messages";
 import { TerrainType } from "#data/terrain";
 import { BattlerTagLapseType } from "#enums/battler-tag-lapse-type";
 import { HeldItemEffect } from "#enums/held-item-effect";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { WeatherType } from "#enums/weather-type";
 import { TurnEndEvent } from "#events/battle-scene";
 import type { Pokemon } from "#field/pokemon";
 import { applyHeldItems } from "#items/all-held-items";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { FieldPhase } from "#phases/field-phase";
 import i18next from "i18next";
 
diff --git a/src/ui/reward-select-ui-handler.ts b/src/ui/reward-select-ui-handler.ts
index 27dead9277b..ddf5c5bc234 100644
--- a/src/ui/reward-select-ui-handler.ts
+++ b/src/ui/reward-select-ui-handler.ts
@@ -7,11 +7,11 @@ import { Button } from "#enums/buttons";
 import type { PokeballType } from "#enums/pokeball";
 import { ShopCursorTarget } from "#enums/shop-cursor-target";
 import { TextStyle } from "#enums/text-style";
+import { TrainerItemEffect } from "#enums/trainer-item-effect";
 import { TrainerItemId } from "#enums/trainer-item-id";
 import { UiMode } from "#enums/ui-mode";
 import type { RewardOption } from "#items/reward";
 import { getPlayerShopRewardOptionsForWave, isTmReward } from "#items/reward-utils";
-import { TrainerItemEffect } from "#items/trainer-item";
 import { AwaitableUiHandler } from "#ui/awaitable-ui-handler";
 import { MoveInfoOverlay } from "#ui/move-info-overlay";
 import { addTextObject, getRarityTierTextTint, getTextColor, getTextStyleOptions } from "#ui/text";