Hakuryuu Ren is the Kou Empire's fourth Prince. Hakuryuu is the owner of the Djinn, Zagan. He is a Dungeon Capturer, capturing one Dungeon, and a King Vessel. He has a large scar on the left side of his face, of which was received during a revolt. He wears traditional clothes typically worn by the Imperial Royalty of Kou. He always carries around a spear, which later becomes his Metal Vessel. He has a wooden prosthetic arm attained through Zagan's power after he loses his arm to Ithnan!