Gatekeeper, Great Demon Master

+1: All demons gain haste and lifelink until end of turn.
-3: Choose one —
-Search your library for any demon card and place it onto the battlefield tapped and attacking, then shuffle your library. Exile it at the end of your turn.
-You may play any demon or sorcery card from exile without paying it's mana cost.
-10: Hell on Earth. You win the game.