Dead Man's Chest is a rare Enchantment — Aura card from Forgotten Realms Commander (AFC), collector number 97. Current market price: $0.70, TCGplayer market prices via Scryfall.
Enchant creature an opponent controls When enchanted creature dies, exile cards equal to its power from the top of its owner's library. You may cast spells from among those cards for as long as they remain exiled, and mana of any type can be spent to cast them.