He's going to go back 3 years to before he achieved OPness and lost all his hair at the age of 22. Look at that hair, isn't it any wonder he gets angry about it. He'll be keeping current memories though.

At this age he's strong, like maybe an average american comic book super hero who's main power ISN'T super strength, but he's probably like 5% the power level he is now and can be hurt. This doesn't really mean much to most characters here, since his strength isn't really known yet, but he will be both excited about having his hair back and maybe asking for some sparring so he can feel that thrill of being beatable again. Feel free to think he's weird for wanting to get potentially beaten up.

He'll be pretty much the same otherwise. He's always been a simple man.