Night Stalker is one of the best gankers in the game and a very fun hero to play as! Make sure you play him mid ONLY, no other lane. You will be roaming a lot (Mostly second night on because the day / night length is shorter as of 6.79.) since you are mid so either try to gank your mid or get a lot of last hits and denies to cover for the time you are not in lane. I focus this build on maxing Void and Hunter in the Night with one point in Crippling Fear BEFORE getting his ult for better ganking potential.