I'm on the Sin mission and have wiped out the bandit camp, released the Duty guy and am now heading for the lab in the other building. The problem is the Monotlith soliders here are invincible. Like emptying 3 magazines into them invincible. I can't kill one of them! I'm a seasoned player so I understand that gun damage, armour and the fact that not all your shots are accurate play a part but I think there's something up here. Spent literally an hour trying to kill one monolith with no success! And that's on novice difficulty. Any ideas?