Leo

Biography
Leo is the lively and blundering twin brother of Luna. He plays a "Morphtronic" deck ("D-Former" in the Japanese version), with transforming monsters that have different abilities in attack and defense position, and his key card is Power Tool Dragon. He idolizes both Yusei and Jack and is always looking after his sister Luna. During a life-or-death battle against Aporia, Leo's desire to protect Luna makes him the sixth and final Signer, with the Mark of the Crimson Dragon's Heart. He also comes into possession of the true form of Power Tool Dragon, Life Stream Dragon, which is also a Synchro Tuner monster which Yusei can use to summon out his strongest monster, Shooting Quasar Dragon.

Manga
In the manga, Leo along with his sister, is a eliminator hired by Rex Goodwin to remove any weak Duelists from the D1GP and to find people that can wield the Duel Dragon cards. Abandoned by their parents when they were young, Leo and Luna entered underground Turbo Dueling to earn money to survive. At first they were a great success but Luna came down with an unknown illness and Leo had to Duel by himself to get enough money to pay for her medicine. Without his sister to cheer him on, Leo began to lose horribly causing people that bet on him to become angry and beat him up. Lazar approached Leo and offered him a job to pay for his sister's medicine. In Duels, both Leo and Luna share a Duel Runner and the same deck consisting of his "Morphtronic" Spell and Trap cards and her "Forest" monster cards. Leo's ace monster is the Duel Dragon: Power Tool Mecha Dragon.