The answer to your problems. No need to fire a single shot. Hunter set all perks to invisibility. Including duration perk. Then set all remaining perks to agility maxed and recovery maxed. Then choose armor that decreases cool down for blink strike. Also choose a gun that increases agility. To start go near the first lamp and kill thrall until you have your super. Go back to starting area and cleanse weight of darkness. Then run to first lamp, either blink strike the first thrall or crouch for invisibility. Alternatively if you can make it to the second lamp without getting melee then do that. THEN crouch or blink for invisibility. Continue this through all the lamps. Remember to pay attention to your cool downs and don't use your super until the ogre or if you're in a pinch. This will take many practice runs to get the rhythm down. Much easier with Don't touch me gauntlets but still possible. Once at the final area activate the plate. Stay there until all the thrall are upon you and blink the closest one. Then run to the lamp in front of you. Ideally you haven't activated this lamp yet. Jump on the rock as your invisibility should have ceased by then. Just before the lamp explodes crouch for invisibility and hop down next to the rock. Then hop back up for safety and go invisible one more time before ogre shows up. At this point all you do is run to the big rock to the left of the little rock. Hide behind it. All the thrall should be by the lamp. Behind this large rock, which is near the far left ledge you can remain undetected, mostly, without being invisible. If you have to, go invisible and run to the next rock. Keep hiding and eventually the bridge will construct and then just run through. The large rocks have small crevasses in them that provide excellent cover. Additionally if you are to far away from the bridge IT WILL NOT BUILD, IT WILL NOT BUILD. You will be waiting for a long time like I did. The key is invisibility management. Remember your super Vanish perk is a last resort. Any questions just ask.