Obelisk the Tormentor

As an additional cost sacrifice 3 creatures.
This card's abilities cannot be countered. When this enters the battlefield, cards and effects cannot be activated. Neither player can target this card with card effects.
Once per turn, during the End Phase, if this card was brought to the battlefield without paying its mana cost: Send it to the GY.
You can sacrifice 2 creatures; destroy all creatures your opponent controls. This card cannot declare an attack the turn this effect is activated.