The Mask of The Oni was a powerful artifact which held a unique control over the Demon race of Oni which resided within the Faewyld and subsequent Faewylds after their release from imprisonment during the Conjunction of the Realms. When the mask is placed upon a creatures face, they are turned into an Oni and forever altered. It is believed that whoever wields the mask holds power over the Oni, although it is customary rite that must one shed the previous owners blood upon the mask before it acclimates to its new owner. The mask was infamously coveted by the Archfey Yokai, the Blood King.