Hour of Reckoning is a rare Sorcery card from Phyrexia: All Will Be One Commander (ONC), collector number 75. Current market price: $0.29, TCGplayer market prices via Scryfall.
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.) Destroy all nontoken creatures.