My extremely lame prediction is Imu has some kind of game-game fruit which is why he has a reversal move that emulates go and why his retainers are immortal, something like they can only be injured by people playing the game. Then the bullshit twist will be Joyboy / Rocks needed to assemble counter 'pieces' to fight him and they both lost because they couldn't field a theoretical team. Its gonna be Kubo tier despite Oda never existing on this level