So I'm not sure if anyone has noticed this yet, but there is a destructible vent cover on the ground in the saber strike. Next to it is a vent that leads to the area where the ultra spawns from. It's directly below the safety glass hidden in the arc smoke. During the strike shanks will spawn from this vent which is why the cover is on the ground. I haven't attempted to make it all the way through the vent yet with a warlock or two, but it looks like once you get through you'll be in the kill zone where the shank door opens up. Like I said though I haven't tried it if anyone wants to. I'm pretty sure if there is a mission for an exotic you will have to enter this vent and drop down to an area below the fight. I've tried glitching into the area from skywatch side and the grottos, but I can't stay out of the map and get the strike fight area to load to see what's under it. Maybe there's some secret to cutting off the power. You can spend time exploring the area by sparrow glitching into the vault in skywatch and re-entering the map during the saber strike. Don't enter from the grottos or you will trigger the warsat which you will have to complete before you can sparrow glitch from that side. Also, most of the vents have automatic doors on them so why put a destructible one on a vent in a hidden area that will kill you if it doesn't lead to something.