Zeno is a self-proclaimed traitor to the Triceraton Empire. He was once a respected Triceraton warrior, but he disagreed with Emporer Zanramon's plan to find the Heart of Darkness. He believed that there is no honor in a weapon that destroys worlds from afar. For saying such things, he was thrown into a pit and became a slave. They only let him out to fight gladiator matches to the death in the Tri-Arena, for the entertainment of the entire empire.