Swift Reckoning is a uncommon Sorcery card from Ultimate Masters (UMA), collector number 39. Current market price: $0.07 (foil $0.35), TCGplayer market prices via Scryfall.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, you may cast this spell as though it had flash. (You may cast it any time you could cast an instant.) Destroy target tapped creature.