Nack in some parts of Mobius is known as Fang the sniper. He is the ultimate enemy on Mobius because neither sonic or Dr. Robotnik likes him since he has betrayed or double-crossed basically everyone. He used to be a member of the chaotix crew until he betrayed them in favor of the brotherhood of mettalix who in turn betrayed him but Nack was prepared and was equipped with a device than neutralized them.