UrRu

The urRu, also most commonly known as Mystics, were a race that inhabited the Valley of the Standing Stones. They originated during Thra's second Great Conjunction, when the Fallen urSkeks attempted to purify themselves through the heat of the three suns shining on the Crystal. Instead of being cleansed of their darker natures, each urSkek was split into two beings; Skeksis and urRu. The urRu were the embodiments of the peaceful, contemplative side of the urSkeks' nature. Their name meant "old and wise ones".[2]

Despite the separation, there was still a spiritual link between each Skeksis and urRu counterpart, a constant reminder that they were only halves of the same being. If either was wounded, the other felt the pain and suffered an identical injury. If one died, both died.