Greatest Show in the Multiverse (UNF-189) - Unfinity Foil [Mythic]

(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.