When you cast this spell, exile all other permanents.

Trample, shround

Whenever Anos Voldigoad, Demon King attacks, defending player exiles the top twenty cards of their library.

Anos Voldigoad, Demon King's power and toughness are each equal to the number of cards in all zones of the game.

If Anos Voldigoad, Demon King would be safrificed, exiled or put into a graveyard from anywhere, reveal Anos Voldigoad, Demon King and shuffle it into its owner's library instead.