Kuai Liang (奎良), better known as Sub-Zero (絶対零度, "Absolute Zero"), Grandmaster (of the Lin Kuei), and formerly known as Tundra and briefly as the cyborg LK-52O, is the Grandmaster of the Lin Kuei assassin clan in the Mortal Kombat fighting game series. Kuai Liang made his playable debut in Mortal Kombat II as the younger brother of Bi-Han, who was the original Sub-Zero in the first Mortal Kombat game. He takes the mantle of Sub-Zero in his later appearances in the series but reappears under his original alias of Tundra in Mortal Kombat (2011) before again going under the mantle of Sub-Zero. Kuai Liang would become a frequent supporting character after his debut. He would later end the long standing rivalry between the Lin Kuei and Shirai Ryu after becoming Grandmaster and making peace with his rival Scorpion.