Age: 17
Rei's defining trait is his competitive drive—he's obsessed with being number one and calls himself "The Number One Star." He lives for intense battles, especially against worthy opponents, and his ultimate goal is to obtain The Ultimate Battle Spirits. True to his obsessive nature, he gets frustrated easily when things don't go his way.
What makes Rei interesting is how his personality shifts depending on which form he takes during battle. His red form, Zero the Burning, taps into his hot-blooded nature and raw aggression. His white form, Zero the Silver, is the opposite—cool, calculated, and serious. This duality lets him adapt his fighting style to whatever the situation demands.
As an ultimate-user and Card Quester, Rei travels across space in his ship, aptly named The Number One Star Ship, hunting for the legendary Ultimate Battle Spirits. His closest companion is Mugen, a dragon who can transform into the card Mugendra. He's also befriended Salt, a robot with an oddly specific talent for making pizza—which probably comes in handy during long space voyages.
Content compiled by AnimeList.moe from publicly available sources.
