Slightly related, but if I were retired today, one of my pet projects would be to train a LLM or whatever to generate new characters for MUGEN[0]. How cool would that be? Maybe the AI could come up with new fighting personas besides the grappler, shotokan, etc. Sounds like a fun project!
I've been reading through the rules to the Fight! RPG by Divine Madness Press and have been similarly looking forward to building characters, moves, and combos for that fight system.
[0] https://en.wikipedia.org/wiki/Mugen_(game_engine)