diff --git a/data/battle_scripts_1.s b/data/battle_scripts_1.s
index 2b3803ab91c2..6ec4da9f3839 100644
--- a/data/battle_scripts_1.s
+++ b/data/battle_scripts_1.s
@@ -8802,6 +8802,17 @@ BattleScript_ActivateSwitchInAbilities_Increment:
 	copybyte gBattlerAttacker, sBATTLER
 	return
 
+BattleScript_ActivateTerrainAbilities:
+	savetarget
+	setbyte gBattlerTarget, 0
+BattleScript_ActivateTerrainAbilities_Loop:
+	activateterrainchangeabilities BS_ATTACKER
+BattleScript_ActivateTerrainAbilities_Increment:
+	addbyte gBattlerTarget, 1
+	jumpifbytenotequal gBattlerTarget, gBattlersCount, BattleScript_ActivateTerrainAbilities_Loop
+	restoretarget
+	return
+
 BattleScript_ElectricSurgeActivates::
 	pause B_WAIT_TIME_SHORT
 	call BattleScript_AbilityPopUp
diff --git a/src/battle_util.c b/src/battle_util.c
index a6c7810ba327..fe4f8d70580f 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -4088,7 +4088,7 @@ static bool32 TryChangeBattleTerrain(u32 battler, u32 statusFlag, u8 *timer)
         else
             *timer = 5;
 
-        gBattlerAttacker = gBattleScripting.battler = battler;
+        gBattleScripting.battler = battler;
         return TRUE;
     }
 
@@ -6066,7 +6066,6 @@ u8 AbilityBattleEffects(u8 caseID, u8 battler, u16 ability, u8 special, u16 move
         }
         break;
     case ABILITYEFFECT_ON_TERRAIN:  // For ability effects that activate when the field terrain changes.
-        battler = gBattlerAbility = gBattleScripting.battler;
         gLastUsedAbility = GetBattlerAbility(battler);
         switch (gLastUsedAbility)
         {
@@ -6075,6 +6074,7 @@ u8 AbilityBattleEffects(u8 caseID, u8 battler, u16 ability, u8 special, u16 move
             {
                 gSpecialStatuses[battler].terrainAbilityDone = TRUE;
                 ChangeTypeBasedOnTerrain(battler);
+                gBattlerAbility = gBattleScripting.battler = battler;
                 BattleScriptPushCursorAndCallback(BattleScript_MimicryActivates_End3);
                 effect++;
             }
@@ -6083,6 +6083,7 @@ u8 AbilityBattleEffects(u8 caseID, u8 battler, u16 ability, u8 special, u16 move
             if (!gSpecialStatuses[battler].terrainAbilityDone && IsBattlerTerrainAffected(battler, STATUS_FIELD_ELECTRIC_TERRAIN))
             {
                 gSpecialStatuses[battler].terrainAbilityDone = TRUE;
+                gBattlerAbility = gBattleScripting.battler = battler;
                 PREPARE_STAT_BUFFER(gBattleTextBuff1, GetHighestStatId(battler));
                 BattleScriptPushCursorAndCallback(BattleScript_QuarkDriveActivates);
                 effect++;
diff --git a/test/battle/ability/seed_sower.c b/test/battle/ability/seed_sower.c
index 7f535cd53cbc..706e43ede576 100644
--- a/test/battle/ability/seed_sower.c
+++ b/test/battle/ability/seed_sower.c
@@ -40,6 +40,10 @@ DOUBLE_BATTLE_TEST("Multi-target moves hit correct battlers after Seed Sower is
         {
             for (l = 0; l < MAX_BATTLERS_COUNT; l++)
             {
+                if (k == l)
+                    continue; // No tests needed when attacker has Seed Sower
+                if ((k & BIT_SIDE) == (l & BIT_SIDE) && moves[j] == MOVE_HYPER_VOICE)
+                    continue; // No tests needed when partners has Seed Sower and Hyper Voice is used.
                 PARAMETRIZE { attacker = l; usedMove = moves[j]; ABILITY_PARAM(0); ABILITY_PARAM(1); ABILITY_PARAM(2); ABILITY_PARAM(3); }
             }
         }
@@ -63,15 +67,25 @@ DOUBLE_BATTLE_TEST("Multi-target moves hit correct battlers after Seed Sower is
         // ANIMATION(ANIM_TYPE_MOVE, usedMove);
         if (usedMove == MOVE_HYPER_VOICE) {
             if ((attacker & BIT_SIDE) == B_SIDE_OPPONENT) {
-                MOVE_HIT(playerLeft, B_POSITION_PLAYER_LEFT);
-                MOVE_HIT(playerRight, B_POSITION_PLAYER_RIGHT);
+                if (attacker == B_POSITION_OPPONENT_LEFT) {
+                    MOVE_HIT(playerLeft, B_POSITION_PLAYER_LEFT);
+                    MOVE_HIT(playerRight, B_POSITION_PLAYER_RIGHT);
+                } else {
+                    MOVE_HIT(playerRight, B_POSITION_PLAYER_RIGHT);
+                    MOVE_HIT(playerLeft, B_POSITION_PLAYER_LEFT);
+                }
                 NONE_OF {
                     HP_BAR(opponentLeft);
                     HP_BAR(opponentRight);
                 }
             } else {
-                MOVE_HIT(opponentLeft, B_POSITION_OPPONENT_LEFT);
-                MOVE_HIT(opponentRight, B_POSITION_OPPONENT_RIGHT);
+                if (attacker == B_POSITION_PLAYER_LEFT) {
+                    MOVE_HIT(opponentLeft, B_POSITION_OPPONENT_LEFT);
+                    MOVE_HIT(opponentRight, B_POSITION_OPPONENT_RIGHT);
+                } else {
+                    MOVE_HIT(opponentRight, B_POSITION_OPPONENT_RIGHT);
+                    MOVE_HIT(opponentLeft, B_POSITION_OPPONENT_LEFT);
+                }
                 NONE_OF {
                     HP_BAR(playerLeft);
                     HP_BAR(playerRight);
@@ -98,7 +112,7 @@ DOUBLE_BATTLE_TEST("Multi-target moves hit correct battlers after Seed Sower is
                 NOT HP_BAR(playerRight);
                 break;
             case B_POSITION_OPPONENT_RIGHT:
-                MOVE_HIT(playerLeft, B_POSITION_OPPONENT_LEFT);
+                MOVE_HIT(playerLeft, B_POSITION_PLAYER_LEFT);
                 MOVE_HIT(opponentLeft, B_POSITION_OPPONENT_LEFT);
                 MOVE_HIT(playerRight, B_POSITION_PLAYER_RIGHT);
                 NOT HP_BAR(opponentRight);