White Steel Fang - S1.E13

The Zeravire have been evolving, not in order to destroy humans, but to ensure the destruction of Gravion. When the new and improved Zeravire comes to Earth to challenge Gravion, Sandman is hesitant to let the Gran Knights go to battle but they refuse to sit on the sidelines. With no other choice, Sandman must authorize the use of Gravions most adavanced weapon.