Rei loves exciting battles , especially with strong opponents.He calls himself "The Number One Star" and is obsessed with being the number one. He gets burned up easily and is very interested in getting the ultimate treasure, The Ultimate Battle Spirits. When he battles, he changes personality, depending on his form. His red form, Zero the Burning, is hotblooded while his white form, Zero the Silver, is more cool and serious. Rei is an ultimate-user and Card Quester. He travels through space.