I did both of my Solohunter runs without ever using a rock to climb on. It´s crucial that you use the small amounts you will be visible as much to your advantage as the parts were you are invisible. What I mean by that: If you are invisible check your surroundings for the nearest enemy and make sure that it`s a thrall (no cursed one), that is not grouped up with others. If your invis runs out draw that thrall by shooting in front of it legs, that will alert the rest of the enemies and they will all rush to your last known position. Let you get hit by that first one and move away from that position, the two greater rockformations far left from the bridge and far right are great for this. Now most of the enemies will be bundled far away from you. Use Blinkstrike or P&T if one or two strollers should find your way to you. Always move crouched, because sound alerts them too. Finally when the Bridge is built up activate your super and get invis. Do´n`t make melees whle your super is on, because you might accidentally hit an enemy and get visible which will be insta-death. Watch out for any Oger that might have already gotten over the bridge. His melee will be a OHK. Concerning Blinkstrike: Never panic-spam it, because the second melee after BS will instantly turn you visible. Hope this helps.