The Order of the Forsaken Forest

This cult worships the corrupted forest and the "Tarnished" beings within. They see the transformations caused by the curse as gifts that lead to enlightenment.
Members undergo rituals to absorb the forest's magic, intentionally inducing transformations as rites of passage. New initiates spend days within the forest alone, exposing themselves to its effects. Many emerge as "Tarnished" loyal to the order and inextricably bonded to the forest's magic, well, the ones that come back out.