The Monster of the Abyss

When you cast The Monster of the Abyss, exile all other non-land permanents. You lose 1 life for each permanent exiled this way.
If a non-Horror creature would enter the battlefield, exile it instead. You lose life equal to its converted mana cost.
"Fight together for all we have ever been and ever will be. Fight for Avelaide our home. Moktaractus has begun. Septhis has come." - The prophet