In Challenge of the Gobots, Cy-Kill was the leader of the evil Renegades. He was originally a member of the Guardians and friend of Leader-1. He wanted to be the sole ruler of Gobotron to better protect it (since he felt he was the mightiest guardian), but Leader-1 believed in democracy. This led Cy-Kill to break away from the Guardians and become the leader of the Renegades. He sought to conquer the Gobot homeworld and have all the power for himself. He was very ruthless and a thorn in the side of the Guardians.