A Metanatural is the offspring of a preternatural and a supernatural. They are extremely rare.
They have the power to steal the supernatural essence of a vampire or a werewolf, becoming that type of creature and rendering their victim human, for the length of a night. This power wears off if the metanatural moves too far away from their victim, if the victim dies while in a human state, if a Preternatural touches them, or when the sun rises. This ability only works at night.
When in werewolf form, the metanatural stays in full control of his or her faculties, with no desire to kill or hunt.
Vampires call them "abominations," "Soul Stealer," or, in older records, "Stealer of Souls." Werewolves call them "Skin Stalker," "Flayer," or, again in old records, "Stalker of Skin." Called "Skin-Thief" by daylight folks.