Ancalagon the Black

+3: Every player loses one life, you gain 3 life.
-7: Target player puts their hand in their graveyard. All of your creatures gain a +2/+2 counter. Destroy 2 target creatures or Planeswalkers.
-10: Control all target player's creatures and Planeswalkers. All of your creatures and Planeswalkers gain flying and a +10/+7 counter.