diff --git a/README.md b/README.md
index 77246fa4402..0f9ed992352 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,7 @@ Check out [Github Issues](https://github.com/pagefaultgames/pokerogue/issues) to
   - Pokémon Sun/Moon
   - Pokémon Ultra Sun/Ultra Moon
   - Pokémon Sword/Shield
+  - Pokémon Legends: Arceus
   - Pokémon Scarlet/Violet
   - Firel (Custom Laboratory, Metropolis, Seabed, and Space biome music)
   - Lmz (Custom Jungle biome music)
diff --git a/public/audio/bgm/battle_legendary_origin_form.mp3 b/public/audio/bgm/battle_legendary_origin_form.mp3
new file mode 100644
index 00000000000..830eeff2f84
Binary files /dev/null and b/public/audio/bgm/battle_legendary_origin_form.mp3 differ
diff --git a/public/audio/bgm/battle_legendary_riders.mp3 b/public/audio/bgm/battle_legendary_riders.mp3
new file mode 100644
index 00000000000..8e9e5f47312
Binary files /dev/null and b/public/audio/bgm/battle_legendary_riders.mp3 differ
diff --git a/src/battle-scene.ts b/src/battle-scene.ts
index 8104d1d4fa9..58ff522c08c 100644
--- a/src/battle-scene.ts
+++ b/src/battle-scene.ts
@@ -1897,6 +1897,8 @@ export default class BattleScene extends SceneBase {
       return 22.770;
     case "battle_legendary_dia_pal": //ORAS Dialga & Palkia Battle
       return 16.009;
+    case "battle_legendary_origin_form": //LA Origin Dialga & Palkia Battle
+      return 18.961;
     case "battle_legendary_giratina": //ORAS Giratina Battle
       return 10.451;
     case "battle_legendary_arceus": //HGSS Arceus Battle
@@ -1925,6 +1927,8 @@ export default class BattleScene extends SceneBase {
       return 12.503;
     case "battle_legendary_calyrex": //SWSH Calyrex Battle
       return 50.641;
+    case "battle_legendary_riders": //SWSH Ice & Shadow Rider Calyrex Battle
+      return 18.155;
     case "battle_legendary_birds_galar": //SWSH Galarian Legendary Birds Battle
       return 0.175;
     case "battle_legendary_ruinous": //SV Treasures of Ruin Battle
diff --git a/src/battle.ts b/src/battle.ts
index 0e10333e6de..cf7efe62ed4 100644
--- a/src/battle.ts
+++ b/src/battle.ts
@@ -275,7 +275,12 @@ export default class Battle {
             return "battle_legendary_sinnoh";
           }
           if (pokemon.species.speciesId === Species.DIALGA || pokemon.species.speciesId === Species.PALKIA) {
-            return "battle_legendary_dia_pal";
+            if (pokemon.getFormKey() === "") {
+              return "battle_legendary_dia_pal";
+            }
+            if (pokemon.getFormKey() === "origin") {
+              return "battle_legendary_origin_form";
+            }
           }
           if (pokemon.species.speciesId === Species.GIRATINA) {
             return "battle_legendary_giratina";
@@ -319,7 +324,12 @@ export default class Battle {
             return "battle_legendary_glas_spec";
           }
           if (pokemon.species.speciesId === Species.CALYREX) {
-            return "battle_legendary_calyrex";
+            if (pokemon.getFormKey() === "") {
+              return "battle_legendary_calyrex";
+            }
+            if (pokemon.getFormKey() === "ice" || pokemon.getFormKey() === "shadow") {
+              return "battle_legendary_riders";
+            }
           }
           if (pokemon.species.speciesId === Species.GALAR_ARTICUNO || pokemon.species.speciesId === Species.GALAR_ZAPDOS || pokemon.species.speciesId === Species.GALAR_MOLTRES) {
             return "battle_legendary_birds_galar";
@@ -504,7 +514,7 @@ export const classicFixedBattles: FixedBattleConfigs = {
     .setGetTrainerFunc(getRandomTrainerFunc([ TrainerType.ROCKET_BOSS_GIOVANNI_1, TrainerType.MAXIE, TrainerType.ARCHIE, TrainerType.CYRUS, TrainerType.GHETSIS, TrainerType.LYSANDRE ])),
   [145]: new FixedBattleConfig().setBattleType(BattleType.TRAINER)
     .setGetTrainerFunc(scene => new Trainer(scene, TrainerType.RIVAL_5, scene.gameData.gender === PlayerGender.MALE ? TrainerVariant.FEMALE : TrainerVariant.DEFAULT)),
-  [165]:  new FixedBattleConfig().setBattleType(BattleType.TRAINER).setSeedOffsetWave(35)
+  [165]: new FixedBattleConfig().setBattleType(BattleType.TRAINER).setSeedOffsetWave(35)
     .setGetTrainerFunc(getRandomTrainerFunc([ TrainerType.ROCKET_BOSS_GIOVANNI_2, TrainerType.MAXIE_2, TrainerType.ARCHIE_2, TrainerType.CYRUS_2, TrainerType.GHETSIS_2, TrainerType.LYSANDRE_2 ])),
   [182]: new FixedBattleConfig().setBattleType(BattleType.TRAINER)
     .setGetTrainerFunc(getRandomTrainerFunc([ TrainerType.LORELEI, TrainerType.WILL, TrainerType.SIDNEY, TrainerType.AARON, TrainerType.SHAUNTAL, TrainerType.MALVA, [ TrainerType.HALA, TrainerType.MOLAYNE ], TrainerType.MARNIE_ELITE, TrainerType.RIKA, TrainerType.CRISPIN ])),
diff --git a/src/locales/en/bgm-name.json b/src/locales/en/bgm-name.json
index 9be8a4b28c7..f02e231178f 100644
--- a/src/locales/en/bgm-name.json
+++ b/src/locales/en/bgm-name.json
@@ -45,6 +45,7 @@
   "battle_legendary_lake_trio": "ORAS Lake Guardians Battle",
   "battle_legendary_sinnoh": "ORAS Sinnoh Legendary Battle",
   "battle_legendary_dia_pal": "ORAS Dialga & Palkia Battle",
+  "battle_legendary_origin_form": "LA Origin Dialga & Palkia Battle",
   "battle_legendary_giratina": "ORAS Giratina Battle",
   "battle_legendary_arceus": "HGSS Arceus Battle",
   "battle_legendary_unova": "BW Unova Legendary Battle",
@@ -59,6 +60,7 @@
   "battle_legendary_zac_zam": "SWSH Zacian & Zamazenta Battle",
   "battle_legendary_glas_spec": "SWSH Glastrier & Spectrier Battle",
   "battle_legendary_calyrex": "SWSH Calyrex Battle",
+  "battle_legendary_riders": "SWSH Ice & Shadow Rider Calyrex Battle",
   "battle_legendary_birds_galar": "SWSH Galarian Legendary Birds Battle",
   "battle_legendary_ruinous": "SV Treasures of Ruin Battle",
   "battle_legendary_kor_mir": "SV Depths of Area Zero Battle",