This lore can be found by an Inquisitor on Voss.
The spirit healers and dream-walkers of Voss are a strange group, even by Voss standards. Preferring to spend most of their time meditating in the wilderness of the Old Paths instead of in Voss-Ka, these Mystics work on healing the mind rather than the body. Using the ritual of dream-walking, the Mystics enter their own minds and face their own fears, hopes, loves and rages, seeking spiritual balance and health. Such spirit healers are few, but there is evidence of their existence throughout Voss history, and an archive of their writings is kept for spirit healer initiates in the Shrine of Healing.