Mephisto, Lord of Hatred

Flying, Deathtouch, Lifelink
At the beginning of your end step, if you untapped four or more permanents this turn, you lose 5 life and Mephisto can't block until your next turn.
For each opponent, if that player controls no Legendary permanents, that player can't attack you unless they pay 3 life for each attacking creature.
Creatures you control get +0/+1