無料BGMや効果音
無料BGM
https://music.yukizakura.net/free/genre/battle.html
http://www.hmix.net/music_gallery/image/buttle.htm
https://amachamusic.chagasi.com/
https://commons.nicovideo.jp/search/tag/%E6%88%A6%E9%97%98
効果音
https://maou.audio/category/bgm/
https://vsq.co.jp/plus/sound/category/environment/