Sigma's true form is that of a computer virus. When takes over a computer system he commands it to build him a body to enslave. When enslaved he destroyes the computer infected. When his body is done he builds his on henchmen. The first one built until (execpt X2 & X4) is Vile. Sigma has been beaten by X and Zero four times. As each time he is beat he grows even more vengeful.
