Savior Mask

The Savior Mask (の仮面), an invention built and developed by Michael Gedōin, can force a demon to possess and remain in a host, regardless of compatibility. It is first used on Izumo Kamiki when it becomes clear that the Nine-Tailed Fox Spirit's possession of her is not taking hold. Gedōin later uses one of a slightly different design on himself and is possessed by a Necrophager.