Thirst Man

Protection from spells and nonlegendary creatures
When Thirst Man enters the battlefield, Tribute 5. (an opponent of your choice may put 5 +1/1 counters on it.)
When Thirst Man enters the battlefield, if tribute wasn't paid, sacrifice 5 creatures you control or force opponent to sacrifice five creatures they control.
Whenever Thirst Man attacks, target creature must block the attack. If no creatures are in the battlefield, if tribute was paid, you win the game.