Zuo Onizuka

Zuo participates in the Shadow Grand Prix. He initially engages Kai Ijuuin in a one-on-one battle, until Kai discovers Ko spying on his hand and communicating it to Zuo. When Kazuki shows up, they decide to continue the match as a tag battle. Zuo and Ko almost win by combining with Dragonsong Flute, but Kai and Kazuki manage to pull off a win. Zuo and Ko are later possessed by Empty Shadows and faces Kazuki in the ruin of the Mythical Card. Hiro joins in middle of the battle to help Kazuki and the two beats Zuo and Ko thanks to Kazuki's Mythical Card. Three years later, during Shadowverse Flame, Zuo participates in the Shadowverse World Ranking where he is seen defeating Fuwari Hahajima. Upon reaching the 8th place of the ranking, both Zuo and Ko are challenged by Subaru Makabe and Itsuki Mitsutagawa. Zuo and Ko are later seen fighting the Shade monsters that invade Nekome City. Upon recieving the Nexa System, Zuo helps Kai to fight the Shades.

Zuo is the champion of the first level of the Underverse Arena. He also participates in the National Tournament, losing to Kazuki Shindō in the first round.

Zou is loud, bellicosity and exuberant, in contrast to his partner Ko, who is quiet and expressionless. He has no qualms about breaking the rules in order to win and "hunt down" his opponents.

Zuo uses a Dragoncraft deck. His main strategy is to use Dragonsong Flute to transform the low cost cards in his hand into powerful Hellflame Dragons to fill the board and overwhelm the opponent. His strategy works in conjunction with Ko's deck when they battle together.

When he becomes possessed by the Empty Shadows, his main card pass to be Voidragon's Flute, wich turn Shadow cards into Shadowflame Dragons.