Cryomancers were once humans native to Outworld who had the ability to control, shape and manipulate ice. Bi-Han, his younger brother Kuai Liang, and Kuai's young apprentice Frost are the only known descendants of the Cryomancers themselves.
Cryomancers are a race native to Outworld. During the earlier period of Shao Kahn's reign as emperor, it is believed that the majority of the population was exterminated, as a result, it is believed that no pure Cryomancers survived into the present day. Appearance-wise, Cryomancers have the appearance of humans, although their actual lifespan is unknown. Their most defining characteristic is that they have the ability to control the moisture in the air around their bodies and cool it into ice, as such, they have the ability to control and manipulate ice. As a result, Cryomancers can use their powers in combat and even form weapons shaped out of ice. Additionally, some Cryomancers seem to have a covering of frost or ice forming on their arms. This particular characteristic may be a result of age as well as level of cryomancy, as the most well known Cryomancer, Kuai Liang developed this feature only recently, whereas the Bi-Han, who was killed at a younger age, and Frost, a younger and less powerful Cryomancer both lacked/lack this feature, this however is purely speculation. Most likely, this is just an ability Sub-Zero uses to strengthen his blows, as he is seen without the ice-sheet in his costumes in Mortal Kombat: Deception. Although, a major factor that contributes to this empowering is the ancient artifact known as the Dragon Medallion, which possesses the power to enhance a Cryomancer's powers to their maximum potential. Some Cryomancers are shown to have very pale that varies to an ice-blue toned skin complexion, a trait shared by Kuai Liang, after his interaction with the Dragon Medallion, and his apprentice, Frost. It is possible that the pure Cryomancers shared this trait.
In her Mortal Kombat: Armageddon ending, Sareena was also said to have gained the Cryomancer freezing ability, maybe even hinting she herself had become one.