Waltz of Rage is a rare Sorcery card from Duskmourn: House of Horror Promos (PDSK), collector number 165p. Current market price: $0.41 (foil $0.35), TCGplayer market prices via Scryfall.
Target creature you control deals damage equal to its power to each other creature. Until end of turn, whenever a creature you control dies, exile the top card of your library. You may play it until the end of your next turn.