You may copy it into other projects and there is no need for you to thank me in credits since none of the assets (Except for the code) are mine (Check Description for sources)
Art - https://dex.pokemonshowdown.com/pokemon/celebi Music - https://downloads.khinsider.com/game-soundtracks/album/pokemon-gold-silver-crystal/85.%2520Battle%2521%2520%2528Legendary%2520Beasts%2529.mp3
