Arrug, Enraged Lavamancer

+1: Exile a card from your graveyard at random. If a red card is exiled this way, Arrug, Enraged Lavamancer deals 1 damage to any target.
-2: You may sacrifice a Mountain. If you do, Arrug, Enraged Lavamancer deals 3 damage to any target.
-7: Exile the top seven cards of your library. You may play those cards this turn.