Bunker D-6 assault

Marked One is teleported into the Bunker D-6 alone to rescue Sparkle and end the Last Day threat.
This quest is unmarked, and doesn't have any canonical name.
==Walkthrough==
=== First floor ===
You appear in a huge room with double doors.
Start taking out the soldiers coming through the double doors, using them as a tiny chokepoint. Once you advance through the doors, five additional soldiers will spawn behind you. After this first wave, there will be another 4 waves each couple minutes of real time. Boxes on the left side of the room provide decent cover from both angles of attack.
Come out of the room, and ascend the spiral staircase. Look out for a turret that guards the exit on the second floor! It will almost immediately shoot at you.
=== Second floor ===
Walk through the double door to the east (with the turret). Beware the second turret immediately to the left of the doors.
In this room, you'll see the control booth and two bulkhead doors.
Save your game and rush through the left one. It will lead you to the main control room with Cold War era computer and radar consoles. Inside, there's a teleport and a soldier standing guard at the right passageway along with natural spawns of a few soldiers in the middle of the room. Lightning is also in that room, and will run for her life into the teleport once she sees you. You only have a few seconds to kill her before she escapes. After killing her, grab her PDA and her broken SVU-A.
Alternatively, you can let her escape. In that case, Vicious will spawn outside of the room; kill him and grab his PDA.
=== Blend's stash ===
If you still remember the Hunt for Fang's killers, you saw a person named Blend at the mercenaries meetup in Dark Valley. Blend was a Last Day member (the first one you've seen in the game), and during The Blend's flash drive he asked you to leave peacefully, promising a present on his base. If you followed his advice and didn't kill him (mercs were alright to kill), he left you a present in the control room where you just killed Lightning or Vicious.
Inside, there will be his PDA with a thankful message to you, saying that he left Last Day.
=== Upper floors ===
Continue ascending the spiral staircase. Beware of the turret on top of the wooden box, immediately at the staircase exit.
On the opposite side of the same floor with the turret, find an open tunnel and try to go through it. It'll teleport you out. Perfumer along with Norman will spawn nearby, having caught up with you.
After both arrive to the tunnel entrance, speak with Perfumer and give him either Lightning's or Vicious' PDA. He will decrypt it with the passwords Sparkle send him earlier, and disable the teleport with it, so you can move on.
=== Tunnel ===
A huge amount of mutants will be ahead along with some Last Day soldiers. Perfumer and Norman are both invincible and will tank the assault.
After the mutant section, you'll stumble upon Sparkle. She is being held in a cell, badly hurt. You cannot heal her, but Perfumer will. She will need to be escorted further to the X-10 Laboratory transition. You will cover her from behind, and Perfumer and Norman volunteer to clear the way forward. Sparkle will trudge along slowly without stopping, but you can tell her to rest temporarily so that you can deal with enemies. She's very fragile, so it's a useful mechanic for keeping her safe.
=== Escorting Sparkle ===
Six Last Day soldiers will spawn behind you, and need to be taken care of before moving on - make sure to tell Sparkle to wait, or she'll wander ahead of Perfumer and Norman who will be stuck on the bloodsucker group ahead.
After dealing with the soldiers, help Perfumer and Norman with the bloodsuckers. They will take care of most of the zombified stalkers up ahead, so just make sure Sparkle doesn't get too far up.
At the end of the area, talk to Perfumer and watch them go. Four Last Day soldiers will spawn behind you, so take them out before leaving to X-10. See Rescuing Sparkle for the next steps.
At this point, you are free to reorganize loot into rucksacks if you want. Beware eight exploding zombies in the room just before the teleport hallway that will harass you while you do so.
==Notes==
* Lure out any naturally spawned soldiers in Lightning's room first before entering if you want to kill her here. The soldier at the doorway will not move and will have to be dealt with later.
* The Remington 870 "Marine Magnum" is a somewhat rare and valuable gun that you can obtain many copies of here. It can be farmed from natural spawns of Last Day in the Dead City and Bunker "D-6".
* Due to the extreme clumping up of Last Day soldiers, especially at the double doors, many guns are bound to fall through the floor and become un-interactable. As always, return after exiting the online radius to reset them.
* You can return to Bunker D-6 any time; feel free to drop a rucksack for loot. However, there's a small natural spawn of Last Day here, and it's unknown whether there are 100% safe spots.
==Bugs==
* If you run far enough into the room, Lightning will actually stop trying to escape and will fight you instead.