User blog comment:Morganaforever/Thoughts on Merlin's finale/@comment-4892425-20121225025711/@comment-5674726-20121225231009

''And no, Morgana won't be tormented for eternity. She is magic, like Merlin, and so she will live eternally, not be sent to the afterlife like Uther. She could join the Disir court, or become one of the incarnations of the Triple Goddess.''

Reincarnation, perhaps? If the Triple Goddess wants Morgana's knowledge of the Old Religion to survive, she could be reborn to resume her role as High Priestess.