The Death of Gwen Stacy is a rare Enchantment — Saga card from Marvel's Spider-Man Promos (PSPM), collector number 54s. Current market price: — (foil $0.95), TCGplayer market prices via Scryfall.
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I — Destroy target creature. II — Each player may discard a card. Each player who doesn't loses 3 life. III — Exile any number of target players' graveyards.