Ob Nixilis, Of vengeance

+5: deal 4 damage to target creature, then draw a card, then you lose 2 life
-X: each opponent loses 2 life unless they discard 2 cards or sacrifices two permanents, repeat this process X times.
-15: each opponent sacrifices 10 permanents, discards their hand, then loses life equal to the number of creatures in each graveyard.