Sub-Zero was the younger brother of the original Sub-Zero who had been killed by Scorpion in the tenth mortal kombat tournament. Sub-Zero had been awakened from the long sleep in the ice coffin. He was in fact the descendent of the long forgotten Necromancer race along with his brother.
Sub-Zero was sent to Outworld with his fellow warrior Smoke in a mission to assassinate Shang Tsung. But when he returns to the Lin Kuei, he and the rest of the clan warriors are taken to become cyborgs. Sub-Zero eventually escapes the clan, while getting a scar on his face during the fight. He finds out his powers in the escape.