Fenwick, Wild Mage

Whenever you cast a spell, you may put it on the bottom of its owner's library. If you do, reveal cards from the top of your library until you reveal a nonland card. You may cast that card without paying its mana cost. Then put all revealed cards
not cast this way on the bottom of your library in a random order. This ability triggers only once each turn.

“Fireball is only for emergencies!”