While the LLS for today is bugged and currently dropping helmets instead of legs, Bungie did acknowledge the issue so hopefully it’ll be fixed up soon. Once it’s dropping appropriately, it looks like it’ll be fairly efficient to farm. Within a few runs I had my time down below 3:30 without much challenge.
Subclass: I did this on Warlock and I prefer mid-tree Stormcaller. The pulse grenade takes out the arc shield in the first main room, and the super burns the final LS boss down from full health.
Kinetic and Energy: I recommend a Scout and SMG. There is only one Arc shield in the Lost Sector and he can be skipped, so there is no reason to optimize for arc damage. I used a Pleiades Corrector for the extra solar damage, and an Extraordinary Rendition. This was a safe loadout to be able to pop Overload champions, Barrior champions, as well as keeping my distance from Vandals.
Power: Xeno is just so good for stuff like this, but if you want your exotic slot elsewhere you could run like Code Duello or something else solar.
Anti-barrier Scout and Overload SMG
Wrath of Rasputin turns your Xeno into a cell generator, and consistently generates cells on Champion kills
Global Reach + Hammer of the Warmind (seasonal mod) will turn your cells into room clearing nukes
Warmind’s protection, Taking Charge, and Protective light are the last few mods I ran just for safety
Machine Gun ammo finder and scavenger to keep your Xeno topped off
You can watch the video for my POV, but this is a really easy LS overall. Run straight up to the Overload Champ, disrupt him then burn with Xeno and a grenade. Use your scout to clear the next room and find a window to pop the Anti-Barrier Servitor with your Xeno. Blow up the Warmind Cell to clear the surrounding adds, clear the room, then open the door. You can skip the guy with the Arc shield, but he fairly consistently drops heavy ammo for me so I just run Arc subclass to take care of him easily. You can burn him with heavy ammo if needed. For the final room, it’s really just about getting the cadence down. You can blow up the Exploding Shanks to clear the first set of adds, then disrupt and Xeno the first Major. He’ll drop a Warmind Cell if using this build, so you can use that to take out the dogs, then burn the next major with Xeno and your Scout to pop the barrier. Kill the final barrier Servitor right away, pick off some adds with your Scout or the WM cell dropped by a champ, and then finish the boss with your super.
I’m very consistently finishing the LS now around the 3:30 mark just playing casually. That’s 12-15 shots at an exotic every hour. Happy farming!