Sentinel of Lost Lore is a rare Creature — Elf Knight card from Wilds of Eldraine (WOE), collector number 358. Current market price: $0.29 (foil $0.32), TCGplayer market prices via Scryfall.
When this creature enters, choose one or more — • Return target card you own in exile that has an Adventure to your hand. • Put target card you don't own in exile that has an Adventure on the bottom of its owner's library. • Exile target player's graveyard.