The Ice Cold of Heaven (墺寒氷天功) is a legendary martial art used by the fifth king of the North Sea Ice Palace to seal the Dragon Turtle.
It could be divided into five forms. It can be made into cold ironstone by injecting cold qi into any hard material such as stone when one reaches the basic third or fourth level. It was written that when one reached the fifth level of cold qi, one could create cold iron with an intensity comparable to the coldest season.