For future references, you should make the game moddable, adding new classes for people to create with different moves and properties. Like modding canon characters, and transformations, etc.

Yeah but he should make an exporting system and also importing inside the game files, that might take a while for a modding system but the easier way is just sending the data of the mod to the servers and when someone joines to the modded player he gets the data

that would be friggin awesome

modding is already a thing