Goku or Superman.
All kidding aside, though? Sasuke. He's the author's chosen Mary Sue and his eyehax powers are basicaly whatever is needed to have him win, or at the very least survive, a fight. His power is the all powerful power of a shitty author pulling author fiat to ensure his precious snowflake never loses.
You can't defeat Sasuke, the most you can hope for is an undecided fight.