This was originally a Standard deck prior to the Shards block rotating out.  It needs the Blightnings and Terminates, so I'm not sure it works in Standard any more. 

This deck was designed for an Allies & U/W Control-heavy metagame.  Hypnotic Specters and Black Nights are a U/W deck's nightmare; both must be responded to quickly and with extreme prejudice, and early, disruptive threats like those can seriously hamper a control player's strategy.  Sarkhan the Mad is an incredible accelerator, but it's easy to run him down out of the range where he's another sac-outlet for Persecutor.  Your best strategy is to use Blightnings to draw out counters and strip aggro spells when hands run low, then stick a Persecutor and ride it to victory....or throw it at your opponent's face.