It's understandable that barrier champions are hard to kill, but when it comes to servitors, there's an unholy, sadistic level of frustration when they make other adds invulnerable [i]while hiding behind many layers of cover[/i]. While I get that the servitor beam looks like a line of sight tether mechanic. The fact that during 1250 and 1280 Lost Sector challenges, the servitor beam regularly IGNORES line-of-sight (LOS) and in-game world Object Collisions in general makes for an insanely frustrating gameplay experience. Not only do Barrier Servitors safely teleport away from danger and get to hide behind cover, but I can't even touch the adds that are guarding it because they're [b]invulnerable through walls[/b]. Although I've many, the single worst experience I've had with seeing the immune beam clipping through walls is when I was chased by 4 immune Wretches in Garden Exodus 2A. When I ran behind a large shipping container, cutting off LOS behind two apparent walls, the Wretches stayed immune and caught up to me. There was nothing I could do but stand there and die while in 'cover' and that was pretty much gameover. Yes, Bungie I know you want these challenges to stay challenges. But I'm sure there's a way to fix these tether mechanics that will actually make the game feel fair and less like a kick in the pants when I'm already down.