For those of you who don't know, mano a mano means hand to hand. The criteria is that no other powers than superstrength, superspeed, durability, life support, stamina, and skill are allowed. No weapons. No BFR. The combatants act in-character but have incentive to win. OK, headbutting and kicking and bodyslams and the like are allowed. Use your best judgement.
Who and why?