Dantalion, Secret Knower

+1: Look at the top card of all decks, you may put those cards back or you may put them anywhere in the deck.
-1: Creatures you don't control get a -1/-5 until end of turn because everyone knows their deepest, darkest secrets and they are embarrassed.
-8: Your opponent has to tell you their deepest, darkest secret. If they tell you, they lose 5 life. If they don't tell you, you win the game.