Deny Reality [Planechase 2012]

Set: Planechase 2012 Type: Sorcery Common Cost: {3}{U}{B} Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.) Return target permanent to its owner's hand.