Those guys at the end of LoA that look like slag guards aren't actually slag guards. Someone I was in a run with got hit by their lance charge and had a red eye floating above his head for the next 30 seconds. The wiki currently says that Cursed Dreadnaughts can only be found inside UFSC, and that Slag guards can be found in FSC and in LoA.
This needs to be changed.
This just happened to me and I came to post the same thing.
I had 1 pip left after I got hit and my teamate died. Let's just say I spent the next 30 seconds running around the last danger room trying to stay alive long enough to use my pill and revive my teamate. Luckily my combuster wasn't cursed so I used the charge to keep the monsters back.