Nis, Labyrinth Breaker

+1: Until end of your opponent's next turn, if Nis dies, return target creature with converted mana cost 5 or less from your graveyard to your hand.
-1: You may spend mana as if it were mana of any color until the end of the turn. Colorless mana is still colorless.
-6: As long as Nis remains in play, your opponent plays with the top card of their library revealed. You may cast nonland cards revealed this way.