Muriel, The Avenger

+4: Target player puts the top half of their library into their graveyard- rounded up. You draw 3 cards.
-3: Muriel, The Avenger deals x damage to target player and each creature they control, where x is equal to the number of cards in your graveyard.
-13: You get an emblem, At the beginning of your upkeep target player loses the game if you control Muriel, The Avenger and his emblem.