Following his defeat, his further descent into madness transcended death, trying to hold onto any grip in the living world, in any form possible, consumed by the lingering thought of killing X. His previous "protection through aggression" philosophy has mutated following his infection into a huge Darwinism complex, believing that anything that is too weak to progress should be annihilated, a la natural selection. He typically looks down on others and does not hesitate to kill the weak, laughing maniacally at their expense. Sigma was originally an honorable and selfless leader of the Maverick Hunters, but after the corruption of Maverick virus inside his body since his last fight against Zero (who at the time was a Maverick), he became a power-hungry tyrant, although even then, he also genuinely believed that he was doing what was in the best interests of the Reploids. He often produces a second form after his initial defeat in a game, which frequently has the head (or the crystal on it) as a weak point.Īlthough Sigma has taken many drastically diverse forms throughout the X series, his humanoid design remains fairly consistent, resembling a giant bald human with a cleft chin. Sigma appears as a bulky, bald humanoid in most of his forms his most pronounced feature is a crystal on his forehead, and two parallel scars running through his eyes. See also: Sigma's alternate costumes in MvC:I