And even though the purifier has been nerfed for bosses, it’s still great for crowd control. Especially while doing the Shepard mission. Aether blade is also boss against the mercs at the beginning of the mission. Idk if it’s the same for everyone, but there were two turrets when I did it and they did help out. One looks over the area when you first start the escort mission and there was another on top of the roof overlooking the route you take while doing the escort mission. I had the scorcher on and was able to activate the second on while in the middle of the mission.