X-43 was part of a series of X-Model Robots created by a top-secret U.S. military project, meant to serve as an army of robotic soldiers capable of acting like humans. When the models began displaying psychotic tendencies due to insufficient programming, they were all destroyed using kill-switches installed in their bodies. The only survivor was the latest robot, X-51, aka Machine Man, who had been raised by Dr. Abel Stack as his own son.
During the A.I. Army's robot revolution, the remains of the destroyed X-Model Robots were bought by Baintronics from the government, and each model was rebuilt using X-51 as a basis. Having determined that free thought was the robots' flaw that made them defective, Arno Stark deprived them of free will, equipping them with a device that transmitted a brainwashing code into their systems.
When the A.I. Army attacked Bain Tower, Arno used Jocasta to lure Machine Man, who was one of the group's key members, into a Baintronics base in New Jersey where he encountered the rebuilt X-Model Robots. While they were attacking Machine Man, he managed to find the cause for their subservience and deployed a counter-frequency that silenced Stark's transmission. The X-Models began to suffer different kinds of mental breakdowns due to their regained autonomy, which allowed Machine Man to go around them and continue looking for Jocasta while a group of Bain-Bots arrived to subdue the X-Models.
- 1 appearance(s) of X-43 (Earth-616)
- 1 minor appearance(s) of X-43 (Earth-616)
- 2 image(s) of X-43 (Earth-616)