Since it is possible to devour an enemy or a treachery card (Reality Acid can let it happen via an elder sign effect), when you return this type of card (and I believe you can choose it), is it going to an encounter deck discard pile (or an investigator's discard pile if it is a weakness)?
Subject 5U-21 deck only.
Fast. Play only during your turn.
If Ravenous (Uncontrolled Hunger) is face up, flip it over. Choose and return up to 3 cards you devoured (beneath Ravenous or set-aside) to their owners' hands. For each card returned in this way, heal 1 damage and 1 horror.