diff --git a/src/field/arena.ts b/src/field/arena.ts
index df5840e0624..413c07dfe9b 100644
--- a/src/field/arena.ts
+++ b/src/field/arena.ts
@@ -8,7 +8,7 @@ import Overrides from "#app/overrides";
 import type { BiomeTierTrainerPools, PokemonPools } from "#balance/biomes";
 import { BiomePoolTier, biomePokemonPools, biomeTrainerPools } from "#balance/biomes";
 import type { ArenaTag } from "#data/arena-tag";
-import { EntryHazardTag, getArenaTag } from "#data/arena-tag";
+import { getArenaTag } from "#data/arena-tag";
 import { SpeciesFormChangeRevertWeatherFormTrigger, SpeciesFormChangeWeatherTrigger } from "#data/form-change-triggers";
 import type { PokemonSpecies } from "#data/pokemon-species";
 import { PositionalTagManager } from "#data/positional-tags/positional-tag-manager";
@@ -431,7 +431,7 @@ export class Arena {
       globalScene.applyModifier(FieldEffectModifier, user.isPlayer(), user, terrainDuration);
     }
 
-    this.terrain = terrain ? new Terrain(terrain, terrainDuration.value, terrainDuration.value) : null;
+    this.terrain = terrain ? new Terrain(terrain, terrainDuration.value) : null;
 
     this.eventTarget.dispatchEvent(new TerrainChangedEvent(this.getTerrainType(), terrainDuration.value));
 
@@ -719,9 +719,7 @@ export class Arena {
     newTag.onAdd(this, quiet);
     this.tags.push(newTag);
 
-    this.eventTarget.dispatchEvent(
-      new ArenaTagAddedEvent(tagType, side, turnCount)
-    );
+    this.eventTarget.dispatchEvent(new ArenaTagAddedEvent(tagType, side, turnCount));
     return true;
   }
 
diff --git a/src/system/game-data.ts b/src/system/game-data.ts
index 323d3869f9d..c2c27d7056c 100644
--- a/src/system/game-data.ts
+++ b/src/system/game-data.ts
@@ -30,7 +30,7 @@ import { StatusEffect } from "#enums/status-effect";
 import { TrainerVariant } from "#enums/trainer-variant";
 import { UiMode } from "#enums/ui-mode";
 import { Unlockables } from "#enums/unlockables";
-import { ArenaTagAddedEvent, WeatherChangedEvent } from "#events/arena";
+import { ArenaTagAddedEvent, TerrainChangedEvent, WeatherChangedEvent } from "#events/arena";
 import type { EnemyPokemon, PlayerPokemon, Pokemon } from "#field/pokemon";
 // biome-ignore lint/performance/noNamespaceImport: Something weird is going on here and I don't want to touch it
 import * as Modifier from "#modifiers/modifier";
@@ -1027,7 +1027,7 @@ export class GameData {
         globalScene.arena.terrain = fromSession.arena.terrain;
         if (fromSession.arena.terrain != null) {
           globalScene.arena.eventTarget.dispatchEvent(
-            new WeatherChangedEvent(
+            new TerrainChangedEvent(
               fromSession.arena.terrain.terrainType,
               fromSession.arena.terrain.turnsLeft,
               fromSession.arena.terrain.maxDuration,
@@ -1035,15 +1035,16 @@ export class GameData {
           );
         }
 
-        globalScene.arena.playerTerasUsed = fromSession.arena.playerTerasUsed;
-
         globalScene.arena.tags = fromSession.arena.tags;
         for (const tag of globalScene.arena.tags) {
           const { tagType, side, turnCount, maxDuration } = tag;
           const layers: [number, number] | undefined =
             tag instanceof EntryHazardTag ? [tag.layers, tag.maxLayers] : undefined;
-          globalScene.arena.eventTarget.dispatchEvent(new ArenaTagAddedEvent(tagType, side, turnCount, layers, maxDuration));
+          globalScene.arena.eventTarget.dispatchEvent(
+            new ArenaTagAddedEvent(tagType, side, turnCount, layers, maxDuration),
+          );
         }
+        globalScene.arena.playerTerasUsed = fromSession.arena.playerTerasUsed;
 
         globalScene.arena.positionalTagManager.tags = fromSession.arena.positionalTags.map(tag =>
           loadPositionalTag(tag),