An Xmen Bioware-type game. It could be just like KotOR where you have an awesome force ability chain. Instead of force abilities your power can be to absorb other powers. Picture having Wolverine's regeneration, Nightcrawler's teleportation, and Jean's telekinesis and telepathy all at the same time. I know this is stretching the capabilities of even current gen consoles but, there should be a time travel mechanic and the game could play differently if you make different decisions, they can have different outcomes. Say, you kill Juggernaut but you want to be evil, you should be able to travel back in time to change that event. Maybe time travel can be one of your powers.