It's really simple. You must figure out who this man is in order to beat him. You've been hired as an assassin from a secret organization, to kill an unknown man. They figured you'd be the best option, because of your status as the best of the best. Sadly, he knows your weaknesses, he adapts easily and has a massive "army" of henchmen he'll send for you. Also don't mind the voice, if you even use those.