Potion of madness and shadow word: pain have extra impact. Combo with twilight acolyte.
Alexstraza, Shadowreaper Anduin, mindblast (+ extra mind blast from shadow vision) Give this deck finishing potential.
Greater Heal Potion + Hero Power gives the deck longevity.
Surprise is your greatest weapon. Anduin on round 8, Alexstraza on round 9, with a powerful burst on round 10 is a deadly finish.