Xormagon, Calamita's End

Flying, Hexproof, Haste
When you cast Xormagon, Calamita's end, sacrifice
half of your permanents, rounded up.
At the beginning of each player's upkeep, that
player sacrifices half of their permanents, rounded
up. If that player didn't sacrifice a permanent this
way, that player loses the game.
When Xormagon dies, you lose the game.