A ritual, whose name was lost to the history, was praticed by the ancient spirit healers on Voss.
This ritual was forbidden, locked away within the Shrine of Healing and guarded by a Voss apparition. The ritual was believed to be powerful enough to restore even the most fractured mind, and involved dream-walking alongside a Gormak. By uniting both Voss and Gormak, it could heal the mind of its "nightmares" by using strange crystal called a dream-rock that was visible only when person was dream-walking and required another person to use it. The rock was used to turn nightmares to flesh in the Spirit World so they became tangible and possible to defeat. By defeating these tangible nightmares, a person gained control over them and by extension his own mind. Lord Kallig used this ritual with the help of Gormak shaman Hadrik to gain control over the Sith spirits they bound to themselves through the use of Force-walking ritual.
- Star Wars: The Old Republic (First appearance)