Was helping a buddy get the spindle, and so we had 2 defender Titans( him and I) and one hunter. I had blessings and he had weapons and the hunter had his tether. Basically jumped up to the boss platform, popped blessings and weapons, and the hunter tethered the boss, and we used exotic swords to take him out. We entered the final room at 7:30 and killed the boss at the 5:00 mark. The rest of the time was used to clear adds. Might work for you. Best of luck!