Chaos Wand

Oracle Text
, : Target opponent exiles cards from the top of their library until they exile an instant or sorcery card. You may cast that card without paying its mana cost. Then put the exiled cards that weren't cast this way on the bottom of that library in a random order.
This could make matches against Approach really interesting. After they cast it the first time you can count down the cards and activate this to force them to fight over the second time they draw it.
Also voltaic servant combos well if you have the mana.