|First Appearance||Ep. 1|
|Key Cards||The DarkDragon Dark-Tyrannosaura|
|X-Rares||The DarkDragon Dark-Tyrannosaura|
Riddle (リドル) is a character in the anime and manga series Saikyo Ginga Ultimate Zero Battle Spirits.
Riddle has blond hair and black eye. On his forehead is a scar. He wears a sleeveless black shirt.
He seems relatively normal, and is weirded out by Rei's form changing, but seems to find Rei interesting.
Riddle is a card battler who faced Rei, with an ultimate crystal at risk. He was defeated.
Later, he met Rei again. Rei considered Riddle a serious friend now, and they decided to have another battle. Riddle didn't expect Rei to use a purple form this time. After the battle, he told Rei news about another ultimate crystal.
He uses a red dark deck.
|The BlackSwordDragon Rexsbeat-Saura||Red||Spirit|
|The DarkDragon Dark-Tyrannosaura||Red||Spirit|
- His deck is similar to Tsurugi Tatewaki's dark deck.