Cosmic Cube

Ward {2} Whenever you attack, look at the top six cards of your library. You may cast a spell from among them with mana value less than or equal to the greatest power among attacking creatures you control without paying its mana cost. Put the rest on the bottom of your library in a random order.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o5fye2vnppb1h53crbhr0.