It's not that difficult Imagine it's a Nightfall strike and go carfeully, once you reach Phogoth don't enter the room nor shoot him From the doorway snipe all the enemies you can, beware of the shrieker in the room Once you clear most of the enemies shoot the boss and release him, lower his health to 25% Keep killing enemies until you see or hear a third dropship Keep shooting enemies from the doorway and wait for Xyor to appear, kill her and your bounty will be complete You don't have to end the boss if you don't want to Good luck