Xi Yan, a half-Uchiha and half-Senju, shone during the Second Shinobi World War. While on a mission to the Land of Water, he accidentally traveled to the pirate world and encountered a sea train bound for Judicial Island! Aboard this speeding train, Xi Yan encountered the boy who carried his destiny. Luffy: Are you a ninja? Xi Yan: Yes. Luffy: Be my partner! Xi Yan: Okay... Since we're here, Xi Yan, invited by Luffy, chose to join the Straw Hat Pirates and adventure with them. He used his power to help his friends rescue Robin and save the ship spirit, Merry! Merry: Xi Yan, what's that? Glancing at Moriah, Xi Yan declared that it was a waste of spirit, a waste who only knew how to rely on external things. ...During the Battle of Marineford, the massive Susanoo wreaked havoc on Marine Headquarters...