Devouring Greed is a uncommon Sorcery — Arcane card from Modern Masters 2015 (MM2), collector number 78. Current market price: $0.11 (foil $0.30), TCGplayer market prices via Scryfall.
As an additional cost to cast this spell, you may sacrifice any number of Spirits. Target player loses 2 life plus 2 life for each Spirit sacrificed this way. You gain that much life.