Garan, Catalyst of Decay

+2: Put the top card of your library into your graveyard. If that card was a creature, put a -1/-1 counter on a creature. Otherwise, draw a card.
-2: Each player puts the top five cards of his or her library into their graveyard, then returns a card at random from their graveyard to their hand.
-X: Exile X cards from your graveyard: Add X mana of any combination of black and green mana to your mana pool.