So if I understand correctly, the moment you would draw a card, if you have 0 cards left in deck, it heals you for the amount of cards left in opponents deck.
If you end your turn with exactly 0 cards in hand it heals you for the number of cards in opponents hand.
Is that right? Or does it work even if it's not exactly 0 cards? (the ability text would suggest otherwise, but then writing about the difference with 0 sounds strange).
What happens when you have this in play, 0 cards left in deck, and you use an Hourglass? If it heals you once again it would be seriously OP.
@mogv Don't you know any other uses of Eternity except preventing a deck out?