Technorg
From Ben10versepedia
Technorg is a Detrovite captured by Slix Vigma to fight in gladiator games. His strength is on par with Fourarms', likely due to several cybernetic enhancements on his left arm, and he has a large mace in place of his left hand. After Ben spares his life, Technorg pledges his life to Ben. Later, he distracts Kevin while Ben (as Cannonbolt) leaves in an escape pod.
Technorg appears in the episode "Grudge Match", and is last seen about to beat up Kevin as the Mega Cruiser leaves for another galaxy. The outcome of their battle remains unclear, but Kevin later assumes control of the Megacruiser while Technorg is not seen again.
For an unknown amount of time he was the Grand Champion of the gladiator games, and when it was feeding time all of the other "contestants" were forced to give him his food as a sign of respect or else Technorg would "punish" them.