The Makluan Berserker is the strongest gladiator of the Makluan race.
When Iron Man, War Machine, Rescue, and Gene Khan defeated the best Makluan gladiators, their overlord released the Berserker. At first they were overwhelmed, but Iron Man detected his weakness in his energy levels. Iron Man took his hammer while War Machine and Rescue fired their unibeams to overload the Berserker and defeat it.
The Berserker is larger than his race's normal size, at least as large as four buses stacked on top of each other. It is as strong as it looks and can endure great levels of trauma.
It can also absorb kinetic energy to make itself stronger, but if it absorbs too much, it overloads and blows up. and gets knocked into a coma. It has a hammer weapon that releases the energy levels when it gets too high.