Greatest Show in the Multiverse is a mythic Artifact Enchantment — Saga card from Unfinity (UNF), collector number 189. Current market price: $0.23 (foil $0.41), TCGplayer market prices via Scryfall.
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) As an additional cost to cast this spell, exile five instant and/or sorcery cards you own with the same artist and different names from outside the game. I, II, III — Choose one of the exiled cards at random. You may cast it without paying its mana cost.