Make a magic battling mod, you know like wands, staffs, spells, magic clothes, VFX and magic leveling system. I've got more detailed description, but won't tell, secret

You can use capability system for storing learned spells, and etc.

There was also a post, in modding forum, I think, about player being a zombie and eating other players and NPC "players."

If you want, we can team up and develop such mod much faster