text: If the source of the damage is a permanent, Retaliator Griffin checks whether an opponent controls that permanent at the time that damage is dealt. If the permanent has left the battlefield by then, its last known information is used. If the source of the damage is a spell, whether it’s controlled by an opponent is obvious. If the source of the damage is a card in some other zone (such as a cycled Jund Sojourners), Retaliator Griffin checks whether the card’s owner, rather than its controller, is an opponent.