Headmaster

Sumdac employee Henry Masterson is fired for creating weapons of war. To take revenge on Sumdac, Masterson uses his exo-suit invention to become "The Headmaster". He eventually succeeds in taking over Bulkhead's body, and fights the Autobots using it and weapons built into the Headmaster unit. He also causes the city's generator-core to overload, threatening to destroy the city. By the time the Autobots defeat Headmaster and knock the Headmaster unit off Bulkhead, the overload is at the point where the only way to stop it is to manually push the containment-grid back into position. However, nobody can survive the conditions inside the core, so it's essentially a suicide mission. At first, Optimus plans to do it himself, but Bulkhead has the idea of creating a new robot to do it. The Autobots create a patchwork robot in time, and Sari animates it with her key. The robot succeeds, and its melted, damaged, inanimate remains are put on display.