Khvostov 7G-OX
To initiate the Khvostov Exotic quest line in Rise of Iron, first you have to dismantle a Year One Khvostov to obtain a blueprint that triggers the quest. If you don’t have one, head to the Divide (via the Plaguelands), and go to the area where you first started the game, and where Ghost found you in vanilla Destiny. There will be a large Fallen ship in the distance. Board the ship, kill all the Fallen, and look for a chest lying in the back of the ship that contains your Khvostov blueprint. This will also help kick-start the quest line.
Next, you’ll have to kill a bunch of enemies to obtain the weapon manual pages, and then you’ll have to hunt down three weapon parts to put the thing together. Once you’ve done all of these, talk to Shiro back at the Iron Temple, and he’ll give you the final quest to hunt down a Fallen major in the Plaguelands. Killing the major will net you your new shiny Auto-rifle, and you’ll get to have a nice, heartwarming chat with Ghost at the end of the quest as well.
You can check out our guide on how to get it here.