Yor Grata, Sire of Eons

+2: Draw 2 cards and put a 0/1 Fog creature token with "{t}: tap target permanent your opponent controls." onto the battlefield.
+4: Discard a card and put a 0/1 Fog creature token with "{t}: tap target permanent your opponent controls." onto the battlefield.
-20: Remove your opponent's library from the game.