Spellshift

Counter target instant or sorcery spell. Its controller reveals cards from the top of their library until they reveal an instant or sorcery card. That player may cast that card without paying its mana cost. Then the player shuffles.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6oq0i6j5w1pb1hy2cjdfxx.