This works every time if you have good coordination in your group. It's easy and fast. I beat it at 299 with two other people below 300. Here is how you do it: Rush to boss room, make sure all people in the group have exotic swords equipped. Raze-lighter is great, but the other swords will help. Get to the boss room with 6 min to 6:30 min remaining. Make sure to pop heavy synth if needed when the timer has 6 min left, so that you can pop another at 1 min remaining. Priority is takin down blights when they appear, there are 3 rounds of them. Then take out boss quick with the following method: Have someone in the group as a night stalker tether, coordinate tethering the boss, have everyone switch to sleeper stimulant and drop the boss with less than 20 total shots (guaranteed crits when boss is tethered). You can drop the boss is less than 1 min this way. Do not leave the entrance area unless you are super or killing blights. Once boss is down kill adds, focusing on blights. If you kill all blights (3 rounds) the timer will actually stop and you can easily finish with 2 minutes remaining. Note: you will probably want to switch to arc rockets with 2 min remaining once the boss is down. Pop a heavy synth if needed.