diff --git a/src/battle-scene.ts b/src/battle-scene.ts
index 4616187e098..d37598f21a3 100644
--- a/src/battle-scene.ts
+++ b/src/battle-scene.ts
@@ -1415,11 +1415,17 @@ export default class BattleScene extends SceneBase {
   }
 
   updateFieldScale(): Promise<void> {
-    return new Promise(resolve => {
-      const fieldScale = Math.floor(Math.pow(1 / this.getField(true)
-        .map(p => p.getSpriteScale())
-        .reduce((highestScale: number, scale: number) => highestScale = Math.max(scale, highestScale), 0), 0.7) * 40
-      ) / 40;
+    return new Promise((resolve) => {
+      const fieldScale =
+        Math.floor(
+          Math.pow(
+            1 /
+              this.getField(true)
+                .map((p) => p.getSpriteScale())
+                .reduce((highestScale: number, scale: number) => (highestScale = Math.max(scale, highestScale)), 0),
+            0.7,
+          ) * 40,
+        ) / 40;
       this.setFieldScale(fieldScale).then(() => resolve());
     });
   }
@@ -2755,12 +2761,11 @@ export default class BattleScene extends SceneBase {
             }
             return true;
           } else {
-            this.addEnemyModifier(newItemModifier, ignoreUpdate, instant).then(() => {
-              if (source && itemLost) {
-                applyPostItemLostAbAttrs(PostItemLostAbAttr, source, false);
-              }
-              return true;
-            });
+            this.addEnemyModifier(newItemModifier, ignoreUpdate, instant);
+            if (source && itemLost) {
+              applyPostItemLostAbAttrs(PostItemLostAbAttr, source, false);
+            }
+            return true;
           }
         }
         return false;
diff --git a/src/data/mystery-encounters/encounters/the-winstrate-challenge-encounter.ts b/src/data/mystery-encounters/encounters/the-winstrate-challenge-encounter.ts
index ca6b384cfbb..7d3f6f4c5bc 100644
--- a/src/data/mystery-encounters/encounters/the-winstrate-challenge-encounter.ts
+++ b/src/data/mystery-encounters/encounters/the-winstrate-challenge-encounter.ts
@@ -151,7 +151,7 @@ async function spawnNextTrainerOrEndEncounter() {
 
     // Give 10x Voucher
     const newModifier = modifierTypes.VOUCHER_PREMIUM().newModifier();
-    await globalScene.addModifier(newModifier);
+    globalScene.addModifier(newModifier);
     globalScene.playSound("item_fanfare");
     await showEncounterText(i18next.t("battle:rewardGain", { modifierName: newModifier?.type.name }));
 
diff --git a/src/data/mystery-encounters/encounters/weird-dream-encounter.ts b/src/data/mystery-encounters/encounters/weird-dream-encounter.ts
index f7c70cb7052..454d179c003 100644
--- a/src/data/mystery-encounters/encounters/weird-dream-encounter.ts
+++ b/src/data/mystery-encounters/encounters/weird-dream-encounter.ts
@@ -406,7 +406,7 @@ async function doNewTeamPostProcess(transformations: PokemonTransformation[]) {
     // Copy old items to new pokemon
     for (const item of transformation.heldItems) {
       item.pokemonId = newPokemon.id;
-      await globalScene.addModifier(item, false, false, false, true);
+      globalScene.addModifier(item, false, false, false, true);
     }
     // Any pokemon that is below 570 BST gets +20 permanent BST to 3 stats
     if (shouldGetOldGateau(newPokemon)) {
@@ -416,7 +416,7 @@ async function doNewTeamPostProcess(transformations: PokemonTransformation[]) {
         ?.withIdFromFunc(modifierTypes.MYSTERY_ENCOUNTER_OLD_GATEAU);
       const modifier = modType?.newModifier(newPokemon);
       if (modifier) {
-        await globalScene.addModifier(modifier, false, false, false, true);
+        globalScene.addModifier(modifier, false, false, false, true);
       }
     }
 
diff --git a/src/data/mystery-encounters/utils/encounter-pokemon-utils.ts b/src/data/mystery-encounters/utils/encounter-pokemon-utils.ts
index 580aaaf2cc6..be7d11d6cf1 100644
--- a/src/data/mystery-encounters/utils/encounter-pokemon-utils.ts
+++ b/src/data/mystery-encounters/utils/encounter-pokemon-utils.ts
@@ -326,7 +326,7 @@ export async function modifyPlayerPokemonBST(pokemon: PlayerPokemon, value: numb
     ?.withIdFromFunc(modifierTypes.MYSTERY_ENCOUNTER_SHUCKLE_JUICE);
   const modifier = modType?.newModifier(pokemon);
   if (modifier) {
-    await globalScene.addModifier(modifier, false, false, false, true);
+    globalScene.addModifier(modifier, false, false, false, true);
     pokemon.calculateStats();
   }
 }
@@ -359,7 +359,7 @@ export async function applyModifierTypeToPlayerPokemon(pokemon: PlayerPokemon, m
     return applyModifierTypeToPlayerPokemon(pokemon, fallbackModifierType);
   }
 
-  await globalScene.addModifier(modifier, false, false, false, true);
+  globalScene.addModifier(modifier, false, false, false, true);
 }
 
 /**
diff --git a/src/phases/add-enemy-buff-modifier-phase.ts b/src/phases/add-enemy-buff-modifier-phase.ts
index d79b4f6eca5..f504fd0aaa2 100644
--- a/src/phases/add-enemy-buff-modifier-phase.ts
+++ b/src/phases/add-enemy-buff-modifier-phase.ts
@@ -21,6 +21,7 @@ export class AddEnemyBuffModifierPhase extends Phase {
     for (let i = 0; i < count; i++) {
       globalScene.addEnemyModifier(getEnemyBuffModifierForWave(tier, globalScene.findModifiers(m => m instanceof EnemyPersistentModifier, false)), true, true);
     }
-    globalScene.updateModifiers(false, true).then(() => this.end());
+    globalScene.updateModifiers(false, true);
+    this.end();
   }
 }
diff --git a/src/phases/modifier-reward-phase.ts b/src/phases/modifier-reward-phase.ts
index 1cdfd6b2721..e4fac33767f 100644
--- a/src/phases/modifier-reward-phase.ts
+++ b/src/phases/modifier-reward-phase.ts
@@ -22,10 +22,9 @@ export class ModifierRewardPhase extends BattlePhase {
   doReward(): Promise<void> {
     return new Promise<void>(resolve => {
       const newModifier = this.modifierType.newModifier();
-      globalScene.addModifier(newModifier).then(() => {
-        globalScene.playSound("item_fanfare");
-        globalScene.ui.showText(i18next.t("battle:rewardGain", { modifierName: newModifier?.type.name }), null, () => resolve(), null, true);
-      });
+      globalScene.addModifier(newModifier);
+      globalScene.playSound("item_fanfare");
+      globalScene.ui.showText(i18next.t("battle:rewardGain", { modifierName: newModifier?.type.name }), null, () => resolve(), null, true);
     });
   }
 }
diff --git a/src/phases/ribbon-modifier-reward-phase.ts b/src/phases/ribbon-modifier-reward-phase.ts
index 8cf15ba8f2c..72a8f4bf37c 100644
--- a/src/phases/ribbon-modifier-reward-phase.ts
+++ b/src/phases/ribbon-modifier-reward-phase.ts
@@ -17,17 +17,16 @@ export class RibbonModifierRewardPhase extends ModifierRewardPhase {
   doReward(): Promise<void> {
     return new Promise<void>(resolve => {
       const newModifier = this.modifierType.newModifier();
-      globalScene.addModifier(newModifier).then(() => {
-        globalScene.playSound("level_up_fanfare");
-        globalScene.ui.setMode(Mode.MESSAGE);
-        globalScene.ui.showText(i18next.t("battle:beatModeFirstTime", {
-          speciesName: this.species.name,
-          gameMode: globalScene.gameMode.getName(),
-          newModifier: newModifier?.type.name
-        }), null, () => {
-          resolve();
-        }, null, true, 1500);
-      });
+      globalScene.addModifier(newModifier);
+      globalScene.playSound("level_up_fanfare");
+      globalScene.ui.setMode(Mode.MESSAGE);
+      globalScene.ui.showText(i18next.t("battle:beatModeFirstTime", {
+        speciesName: this.species.name,
+        gameMode: globalScene.gameMode.getName(),
+        newModifier: newModifier?.type.name,
+      }), null, () => {
+        resolve();
+      }, null, true, 1500);
     });
   }
 }
diff --git a/src/phases/select-modifier-phase.ts b/src/phases/select-modifier-phase.ts
index a3a2fa1aa24..36f18a8d64d 100644
--- a/src/phases/select-modifier-phase.ts
+++ b/src/phases/select-modifier-phase.ts
@@ -171,30 +171,21 @@ export class SelectModifierPhase extends BattlePhase {
         }
 
         if (cost && !(modifier.type instanceof RememberMoveModifierType)) {
-          result.then(success => {
-            if (success) {
-              if (!Overrides.WAIVE_ROLL_FEE_OVERRIDE) {
-                globalScene.money -= cost;
-                globalScene.updateMoneyText();
-                globalScene.animateMoneyChanged(false);
-              }
-              globalScene.playSound("se/buy");
-              (globalScene.ui.getHandler() as ModifierSelectUiHandler).updateCostText();
-            } else {
-              globalScene.ui.playError();
+          if (result) {
+            if (!Overrides.WAIVE_ROLL_FEE_OVERRIDE) {
+              globalScene.money -= cost;
+              globalScene.updateMoneyText();
+              globalScene.animateMoneyChanged(false);
             }
-          });
-        } else {
-          const doEnd = () => {
-            globalScene.ui.clearText();
-            globalScene.ui.setMode(Mode.MESSAGE);
-            super.end();
-          };
-          if (result instanceof Promise) {
-            result.then(() => doEnd());
+            globalScene.playSound("se/buy");
+            (globalScene.ui.getHandler() as ModifierSelectUiHandler).updateCostText();
           } else {
-            doEnd();
+            globalScene.ui.playError();
           }
+        } else {
+          globalScene.ui.clearText();
+          globalScene.ui.setMode(Mode.MESSAGE);
+          super.end();
         }
       };
 
@@ -304,7 +295,7 @@ export class SelectModifierPhase extends BattlePhase {
     );
   }
 
-  addModifier(modifier: Modifier): Promise<boolean> {
+  addModifier(modifier: Modifier): boolean {
     return globalScene.addModifier(modifier, false, true);
   }
 }
diff --git a/src/test/mystery-encounter/encounters/clowning-around-encounter.test.ts b/src/test/mystery-encounter/encounters/clowning-around-encounter.test.ts
index f105678e71f..f95450bbf44 100644
--- a/src/test/mystery-encounter/encounters/clowning-around-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/clowning-around-encounter.test.ts
@@ -375,6 +375,6 @@ describe("Clowning Around - Mystery Encounter", () => {
 async function addItemToPokemon(scene: BattleScene, pokemon: Pokemon, stackCount: number, itemType: PokemonHeldItemModifierType) {
   const itemMod = itemType.newModifier(pokemon) as PokemonHeldItemModifier;
   itemMod.stackCount = stackCount;
-  await scene.addModifier(itemMod, true, false, false, true);
+  scene.addModifier(itemMod, true, false, false, true);
   await scene.updateModifiers(true);
 }
diff --git a/src/test/mystery-encounter/encounters/delibirdy-encounter.test.ts b/src/test/mystery-encounter/encounters/delibirdy-encounter.test.ts
index f99aa24805e..8121916a4d7 100644
--- a/src/test/mystery-encounter/encounters/delibirdy-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/delibirdy-encounter.test.ts
@@ -123,7 +123,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       scene.modifiers = [];
       const amuletCoin = generateModifierType(modifierTypes.AMULET_COIN)!.newModifier() as MoneyMultiplierModifier;
       amuletCoin.stackCount = 5;
-      await scene.addModifier(amuletCoin, true, false, false, true);
+      scene.addModifier(amuletCoin, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 1);
@@ -193,7 +193,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       const sitrus = generateModifierType(modifierTypes.BERRY, [ BerryType.SITRUS ])!;
       const sitrusMod = sitrus.newModifier(scene.getPlayerParty()[0]) as BerryModifier;
       sitrusMod.stackCount = 2;
-      await scene.addModifier(sitrusMod, true, false, false, true);
+      scene.addModifier(sitrusMod, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 2, { pokemonNo: 1, optionNo: 1 });
@@ -214,7 +214,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       const revSeed = generateModifierType(modifierTypes.REVIVER_SEED)!;
       const modifier = revSeed.newModifier(scene.getPlayerParty()[0]) as PokemonInstantReviveModifier;
       modifier.stackCount = 1;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 2, { pokemonNo: 1, optionNo: 1 });
@@ -234,13 +234,13 @@ describe("Delibird-y - Mystery Encounter", () => {
       scene.modifiers = [];
       const candyJar = generateModifierType(modifierTypes.CANDY_JAR)!.newModifier() as LevelIncrementBoosterModifier;
       candyJar.stackCount = 99;
-      await scene.addModifier(candyJar, true, false, false, true);
+      scene.addModifier(candyJar, true, false, false, true);
       const sitrus = generateModifierType(modifierTypes.BERRY, [ BerryType.SITRUS ])!;
 
       // Sitrus berries on party
       const sitrusMod = sitrus.newModifier(scene.getPlayerParty()[0]) as BerryModifier;
       sitrusMod.stackCount = 2;
-      await scene.addModifier(sitrusMod, true, false, false, true);
+      scene.addModifier(sitrusMod, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 2, { pokemonNo: 1, optionNo: 1 });
@@ -263,13 +263,13 @@ describe("Delibird-y - Mystery Encounter", () => {
       scene.modifiers = [];
       const healingCharm = generateModifierType(modifierTypes.BERRY_POUCH)!.newModifier() as PreserveBerryModifier;
       healingCharm.stackCount = 3;
-      await scene.addModifier(healingCharm, true, false, false, true);
+      scene.addModifier(healingCharm, true, false, false, true);
 
       // Set 1 Reviver Seed on party lead
       const revSeed = generateModifierType(modifierTypes.REVIVER_SEED)!;
       const modifier = revSeed.newModifier(scene.getPlayerParty()[0]) as PokemonInstantReviveModifier;
       modifier.stackCount = 1;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 2, { pokemonNo: 1, optionNo: 1 });
@@ -292,7 +292,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       scene.modifiers = [];
       const soulDew = generateModifierType(modifierTypes.SOUL_DEW)!;
       const modifier = soulDew.newModifier(scene.getPlayerParty()[0]);
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await game.phaseInterceptor.to(MysteryEncounterPhase, false);
@@ -321,7 +321,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       const revSeed = generateModifierType(modifierTypes.REVIVER_SEED)!;
       const modifier = revSeed.newModifier(scene.getPlayerParty()[0]) as PokemonInstantReviveModifier;
       modifier.stackCount = 1;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 2, { pokemonNo: 1, optionNo: 1 });
@@ -355,7 +355,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       const soulDew = generateModifierType(modifierTypes.SOUL_DEW)!;
       const modifier = soulDew.newModifier(scene.getPlayerParty()[0]) as PokemonNatureWeightModifier;
       modifier.stackCount = 2;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 3, { pokemonNo: 1, optionNo: 1 });
@@ -376,7 +376,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       const soulDew = generateModifierType(modifierTypes.SOUL_DEW)!;
       const modifier = soulDew.newModifier(scene.getPlayerParty()[0]) as PokemonNatureWeightModifier;
       modifier.stackCount = 1;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 3, { pokemonNo: 1, optionNo: 1 });
@@ -396,13 +396,13 @@ describe("Delibird-y - Mystery Encounter", () => {
       scene.modifiers = [];
       const healingCharm = generateModifierType(modifierTypes.HEALING_CHARM)!.newModifier() as HealingBoosterModifier;
       healingCharm.stackCount = 5;
-      await scene.addModifier(healingCharm, true, false, false, true);
+      scene.addModifier(healingCharm, true, false, false, true);
 
       // Set 1 Soul Dew on party lead
       const soulDew = generateModifierType(modifierTypes.SOUL_DEW)!;
       const modifier = soulDew.newModifier(scene.getPlayerParty()[0]) as PokemonNatureWeightModifier;
       modifier.stackCount = 1;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 3, { pokemonNo: 1, optionNo: 1 });
@@ -425,7 +425,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       scene.modifiers = [];
       const revSeed = generateModifierType(modifierTypes.REVIVER_SEED)!;
       const modifier = revSeed.newModifier(scene.getPlayerParty()[0]);
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await game.phaseInterceptor.to(MysteryEncounterPhase, false);
@@ -455,7 +455,7 @@ describe("Delibird-y - Mystery Encounter", () => {
       const soulDew = generateModifierType(modifierTypes.SOUL_DEW)!;
       const modifier = soulDew.newModifier(scene.getPlayerParty()[0]) as PokemonNatureWeightModifier;
       modifier.stackCount = 1;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 3, { pokemonNo: 1, optionNo: 1 });
diff --git a/src/test/mystery-encounter/encounters/global-trade-system-encounter.test.ts b/src/test/mystery-encounter/encounters/global-trade-system-encounter.test.ts
index fb5801c941a..60780984014 100644
--- a/src/test/mystery-encounter/encounters/global-trade-system-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/global-trade-system-encounter.test.ts
@@ -224,7 +224,7 @@ describe("Global Trade System - Mystery Encounter", () => {
       const soulDew = generateModifierType(modifierTypes.SOUL_DEW)!;
       const modifier = soulDew.newModifier(scene.getPlayerParty()[0]) as PokemonNatureWeightModifier;
       modifier.stackCount = 2;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 3, { pokemonNo: 1, optionNo: 1 });
@@ -249,7 +249,7 @@ describe("Global Trade System - Mystery Encounter", () => {
       const soulDew = generateModifierType(modifierTypes.SOUL_DEW)!;
       const modifier = soulDew.newModifier(scene.getPlayerParty()[0]) as PokemonNatureWeightModifier;
       modifier.stackCount = 1;
-      await scene.addModifier(modifier, true, false, false, true);
+      scene.addModifier(modifier, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 3, { pokemonNo: 1, optionNo: 1 });
diff --git a/src/test/mystery-encounter/encounters/uncommon-breed-encounter.test.ts b/src/test/mystery-encounter/encounters/uncommon-breed-encounter.test.ts
index 39904c030a3..06bd382879f 100644
--- a/src/test/mystery-encounter/encounters/uncommon-breed-encounter.test.ts
+++ b/src/test/mystery-encounter/encounters/uncommon-breed-encounter.test.ts
@@ -216,11 +216,11 @@ describe("Uncommon Breed - Mystery Encounter", () => {
       const sitrus = generateModifierType(modifierTypes.BERRY, [ BerryType.SITRUS ])!;
       const sitrusMod = sitrus.newModifier(scene.getPlayerParty()[0]) as BerryModifier;
       sitrusMod.stackCount = 2;
-      await scene.addModifier(sitrusMod, true, false, false, true);
+      scene.addModifier(sitrusMod, true, false, false, true);
       const ganlon = generateModifierType(modifierTypes.BERRY, [ BerryType.GANLON ])!;
       const ganlonMod = ganlon.newModifier(scene.getPlayerParty()[0]) as BerryModifier;
       ganlonMod.stackCount = 3;
-      await scene.addModifier(ganlonMod, true, false, false, true);
+      scene.addModifier(ganlonMod, true, false, false, true);
       await scene.updateModifiers(true);
 
       await runMysteryEncounterToEnd(game, 2);