Elspeth's Nightmare is a uncommon Enchantment — Saga card from Theros Beyond Death (THB), collector number 91. Current market price: $0.23 (foil $0.39), 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 an opponent controls with power 2 or less. II — Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card. III — Exile target opponent's graveyard.