diff --git a/data/battle_scripts_1.s b/data/battle_scripts_1.s
index 4e29e3be03..356723daab 100644
--- a/data/battle_scripts_1.s
+++ b/data/battle_scripts_1.s
@@ -8023,9 +8023,12 @@ BattleScript_SupremeOverlordActivates::
 
 BattleScript_CostarActivates::
 	pause B_WAIT_TIME_SHORT
+	savetarget
+	copybyte gBattlerTarget, sBATTLER
 	call BattleScript_AbilityPopUp
 	printstring STRINGID_PKMNCOPIEDSTATCHANGES
 	waitmessage B_WAIT_TIME_LONG
+	restoretarget
 	end3
 
 BattleScript_ZeroToHeroActivates::
diff --git a/src/battle_util.c b/src/battle_util.c
index 38e4b1e61d..a8e8ebcd39 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -4980,10 +4980,10 @@ u32 AbilityBattleEffects(u32 caseID, u32 battler, u32 ability, u32 special, u32
              && CountBattlerStatIncreases(BATTLE_PARTNER(battler), FALSE))
             {
                 gSpecialStatuses[battler].switchInAbilityDone = TRUE;
-                gBattlerAttacker = battler;
+                gBattlerAttacker = gBattlerAbility = battler;
                 for (i = 0; i < NUM_BATTLE_STATS; i++)
                     gBattleMons[battler].statStages[i] = gBattleMons[BATTLE_PARTNER(battler)].statStages[i];
-                gBattlerTarget = BATTLE_PARTNER(battler);
+                gBattleScripting.battler = BATTLE_PARTNER(battler);
                 BattleScriptPushCursorAndCallback(BattleScript_CostarActivates);
                 effect++;
             }
diff --git a/test/battle/ability/costar.c b/test/battle/ability/costar.c
index 7674ab0966..c42871bb45 100644
--- a/test/battle/ability/costar.c
+++ b/test/battle/ability/costar.c
@@ -1,7 +1,29 @@
 #include "global.h"
 #include "test/battle.h"
 
-TO_DO_BATTLE_TEST("Costar copies an ally's stat stages upon entering battle");
+DOUBLE_BATTLE_TEST("Costar copies an ally's stat stages upon entering battle")
+{
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET);
+        PLAYER(SPECIES_WOBBUFFET);
+        OPPONENT(SPECIES_WOBBUFFET);
+        OPPONENT(SPECIES_WYNAUT);
+        OPPONENT(SPECIES_FLAMIGO) { Ability(ABILITY_COSTAR); }
+    } WHEN {
+        TURN { MOVE(opponentLeft, MOVE_SWORDS_DANCE); }
+        TURN { SWITCH(opponentRight, 2); MOVE(playerLeft, MOVE_CELEBRATE); }
+    } SCENE {
+        // Turn 1 - buff up
+        MESSAGE("Foe Wobbuffet used Swords Dance!");
+        ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponentLeft);
+        // Turn 2 - Switch into Flamigo
+        MESSAGE("2 sent out Flamigo!");
+        ABILITY_POPUP(opponentRight, ABILITY_COSTAR);
+        MESSAGE("Foe Flamigo copied Foe Wobbuffet's stat changes!");
+    } THEN {
+        EXPECT_EQ(opponentRight->statStages[STAT_ATK], DEFAULT_STAT_STAGE + 2);
+    }
+}
 
 // Copy from Ruin ability tests
 TO_DO_BATTLE_TEST("Costar's message displays correctly after all battlers fainted - Player");
diff --git a/test/battle/ability/download.c b/test/battle/ability/download.c
index 9fecda400d..e96b0ddeb9 100644
--- a/test/battle/ability/download.c
+++ b/test/battle/ability/download.c
@@ -94,3 +94,28 @@ SINGLE_BATTLE_TEST("Download doesn't activate if target hasn't been sent out yet
         EXPECT_MUL_EQ(results[0].damageSpecial, Q_4_12(1.5), results[1].damageSpecial);
     }
 }
+
+DOUBLE_BATTLE_TEST("Download raises Sp.Attack if enemies have lower total Sp. Def than Def", s16 damage)
+{
+    u32 ability;
+    PARAMETRIZE { ability = ABILITY_TRACE; }
+    PARAMETRIZE { ability = ABILITY_DOWNLOAD; }
+    GIVEN {
+        PLAYER(SPECIES_PORYGON) { Ability(ability); SpAttack(100); }
+        PLAYER(SPECIES_WYNAUT);
+        OPPONENT(SPECIES_WOBBUFFET) { Defense(200); SpDefense(100); }
+        OPPONENT(SPECIES_WOBBUFFET) { Defense(100); SpDefense(150); }
+    } WHEN {
+        TURN { MOVE(playerLeft, MOVE_TRI_ATTACK, target: opponentLeft ); }
+    } SCENE {
+        if (ability == ABILITY_DOWNLOAD)
+        {
+            ABILITY_POPUP(playerLeft, ABILITY_DOWNLOAD);
+            ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, playerLeft);
+            MESSAGE("Porygon's Download raised its Sp. Atk!");
+        }
+        HP_BAR(opponentLeft, captureDamage: &results[i].damage);
+    } FINALLY {
+        EXPECT_MUL_EQ(results[0].damage, Q_4_12(1.5), results[1].damage);
+    }
+}