The Nightstalker is one of the new subclasses included in Destiny: The Taken King. Getting a new subclass is not so immediate as one could expect, so read our guide in case you are encountering troubles in unlocking it. First of all, you need to beat the first part of The Taken King main quest. Return to the Tower and get the quest “The Nightstalker’s Trail” from the Hunter Vanguard Quartermaster. You will have to play in solo mode and travel to Venus.
Once there, go to the objective marker, beat all the Vex you will find on your path and go for the second objective. Locate the a dead ghost and scan it, then you will be able to find Tevis and unlock the Nightstalker subclass.
You will have to use it instantly, as you will need to defeat new enemies and avenge Tevis. Don’t forget to return to the Tower once you have completed the quest in order to get XP and a new piece of armor.