Keldon Flamesage [Dominaria United]

Set: Dominaria United Type: Creature — Human Shaman Rarity: Rare Cost: {2}{R} Enlist Whenever Keldon Flamesage attacks, look at the top X cards of your library, where X is Keldon Flamesage's power. You may exile an instant or sorcery card with mana value X or less from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost.