Demon Mask (5e Equipment)
From D&D Wiki
Wondrous item, Rare (Requires Attunement)
This mask bears an uncanny likeness to that of a Succubus. It almost seems to beckon people to put it on.
Donning or doffing it requires a bonus action. If the creature wearing the mask is attuned to it, it shapeshifts into a Succubus until the mask is taken off with a successful DC 16 Charisma check.
If the creature wearing the mask is not attuned to it, the mask will automatically attune itself to the creature over a period of 1 hour, during which the mask will gradually shapeshift the creature into a Succubus.