Ichibanboshi no Rei

一番星のレイ

Rei enjoys thrilling battles, particularly when facing a formidable opponent. He refers to himself as "The Number One Star" and is fixated on achieving the top rank. He gets fired up easily and is deeply interested in obtaining the ultimate treasure, The Ultimate Battle Spirits.
His personality shifts depending on his form during battle. His red form, Zero the Burning, is hot-blooded, whereas his white form, Zero the Silver, is cooler and more serious.
Rei is an ultimate-user and Card Quester searching for The Ultimate Battle Spirits. He travels through space aboard his vessel, The Number One Star Ship. His partner is a dragon named Mugen, who transforms into the card Mugendra. He is also friends with a robot named Salt, who prepares pizza.