Emergent Ultimatum is a rare Sorcery card from Ikoria: Lair of Behemoths (IKO), collector number 333. Current market price: $1.31 (foil $2.17), TCGplayer market prices via Scryfall.
Search your library for up to three monocolored cards with different names and exile them. An opponent chooses one of those cards. Shuffle that card into your library. You may cast the other cards without paying their mana costs. Exile Emergent Ultimatum.