Emrakul's Omen bearer

When Emrakul's Omen bearer enters the battlefield, destroy all non-legendary non-land permanents you control. Then search your library
for a permanent card with mana value X or less, reveal it and cast it without paying its mana cost, where X is the number of permanents that were sacrificed this way.

"as it flew closer it's eldritch brethren fell, thats
when a shadow loomed over us..."