Every successful pirate captain is supported by an equally impressive first mate, and luckily for One Piece's protagonist, Monkey D. Luffy, his most trusted ally has proven himself to be one of the most reliable pirates sailing the Grand Line. Roronoa Zoro joins the Straw Hat Pirates in the series' third episode, immediately demonstrating an unparalleled determination to become the World's Strongest Swordsman. However, in order to accomplish his goal, the three-sword-style fighter will need to defeat a long list of accomplished swordsmen, each of whom wields a blade that gives life to their respective journeys.
Source：https://www.cbr.com/one-piece-roronoa-zoro-will-earn-black-blade-by-beating-dracule-mihawk/
