His nickname is "Hawk-Eye" Mihawk. One of the Seven Warlords of the Sea and the world's greatest swordsman. He can even slice a gigantic ship into 2 with a single blow. He rivaled Shanks, but lost interest when he lost his left arm. One thing he never really does is laugh or even smile. With the Black Sword he calls "Yoru" , strapped to his back, he hunts pirates on his own. He is seemingly bored and hunts pirates to pass time. Even in One Piece verse, he is quite an unknown figure.