Obelisk The Tormentor

You must send three creatures you controle to the graveyard in addition to casting this. No other card or effects can be activated and/or cast in response to this being cast. This cannot be summoned in any other way.
This cannot be targeted and/or destroyed by card effects.
{10} You may send two creatures you controle to the Graveyard, and if you do, you can destroy all Creatures your opponent controls, this cannot attack on the turn you activate this effect.