rename devilsknife to chaos scythe and make ralsei = asriel cannon (change ralsei's sprite sheet to asirels) and when you give "asriel" the chaos scythe he says "hey he ripped off my weapon" lol
it wont work because to progress the game you need to use teacup
and only noelle can use spells but she does not have a roll animation for teacups
so the game craches