He is  Seven Barian Emperors's leader. But he was "Reginald Kastle", the human. And he have younger sister, Rio Kastle, and Rio Kastle's Barian name is "Marin". When he was human, he have friend Yuma Tsukumo and Kite Tenjo. And he won their enemy, like Dr. Faker. When ZEXAL II, Barian Seven Emepors invaded human world, and he found his Mythyrian Numbers, "Number 73: Abyss Splash". But he and Rio found out who they were because of Dumon. They were Seven Barian Emperor's member, and he is leader.