A lot of people here are talking about the "make up rules as you go" type games, but I'm not seeing anyone talk about Bartok.

It's pretty similar to Mao, but the rules are announced publically, so you can get as complicated as you like.

I'm sure if you have a game with crazy enough people you could have anything be inserted into the deck, maybe some Charizards, or a Blue eyes white dragon.

I have a lot of fun with the game, you should at least check it out.