Maven, Malignant Mistress

+2: Target player puts the top three cards of their library into their graveyard, scry 3
-X: Exile X cards from target player's graveyard, create an X/X black horror creature token with lifelink and trample
-7: You get an emblem with "Whenever an opponent loses life, that player puts that many cards from the top of their library into their graveyard"