Rot Farm Earthturner

Scavenge abilities you activate cost {2} less to activate.
Whenever you activate a scavenge ability of a creature card in your graveyard, mill four cards.
Scavenge {4}{b}{g} ({4}{b}{g}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)