Sigma

Sigma is considered by all to be the deadliest and most sinister of all the Mavericks. Originally the leader of the Maverick Hunters until a chance encounter with a virus corrupted and altered his systems to turn him into the enemy of mankind he is today. A constant thorn in the sides of X and Zero, Sigma devises a steady stream of deadly plots and traps to test the Hunters' resolve again and again. He briefly entered into an allegiance with the mysterious being known only as 'The Doctor' until a falling out in which he terminated the Doctor's existence. This lead to him revealing to the Hunters that he had survived their last battle on the moon. This revelation resulted in the total annihilation of a major city which led to a staggering loss of life.