Ren Suzugamori  

It is also known that Ren became the best national player because he used the power Psyqualia to win. Because he has been using Psyqualia for a few years, it isn't under control and it is extremely powerful. Ren's strongest cards are: Blaster Dark, Phantom Blaster Dragon, Phantom Blaster Overlord, Spectral Duke Dragon, Revenger, Raging Form DragonRevenger, Dragruler Phantom, and Revenger, Phantom Blaster "Abyss". Later it is revealed that he was a friend of Kai, who got mad due to a power he had called Psyqualia. That power made Ren claim that the cards of his deck were talking to him and telling him how to win every fight. Psyqualia made Ren lose himself and turn him into a selfish guy, who created the Team Foo Fighter, whose members are the best Vanguard players of the country. Kai leaves Ren when he notices Ren is taking things too far, and he goes back to his childhood town in order to run from Ren.