Keldon Flamesage (Extended Art) (DMU-407) - Dominaria United: (Extended Art)

Enlist
Whenever this creature attacks, look at the top X cards of your library, where X is this creature'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.