Bringer of the Abyss

When Bringer of the Abyss enters the battlefield,
each opponent sacrifices four permanents.
Flying, shroud
{4}, sacrifice two permanents: This creature loses
shroud until end of turn. Any player may activate
this ability.
At the beginning of each opponent's upkeep and
end step, that player sacrifices two permanents.
If an opponent doesn't have a permanent in play,
they lose the game.