Pirate hunter

 Zoro, also known as "Pirate Hunter" , is a main combatant of the Straw cap Pirates, one of their two swordsmen, one of the Senior Officers of the Straw cap Grand Fleet, and is publicly recognized as the right-hand man of his crew's captain Monkey D Lucy. Formerly a bounty hunter, he is the second member of Lucy's crew and the first to join it, doing so in the Romance  Arc.