In multiplayer nothing will pause the game, and you said "we" so I assume you are playing with someone else. If you run past them, they will stay down in the underground area and you can complete the rest of the dungeon without them bugging you. They are slow and easy to outrun as long as you duck into cover if they start charging up a freeze ray. I'm tellin you man, we were so persistant in our efforts to kill them, but we found it to be impossible. We went as far as to splitting them up and fighting them one on one, which made things possible, but not easy as it was still taking forever to take down their life. As for fighting two at the same time, I dont think its gonna happen bro. One idea my brother had is that you are suppose to make them kill each other, but we didnt try that. If you are dead set on killing them, the overhead chop does work but you have to be right in their face to hit them. I found that shielding their freeze attack will only work a few times until it goes past your shield, or maybe that was just me messing up blocking.
The exit of that underground area isnt a door or a ramp, but its actually a large ledge you must jump on top of to climb out. If you noticed the bone-infused pillars along the hallway of the labrinth, it looks a lot like one of those only tipped over on its side. I think its in the north section of the underground part.
I think they are about 5k exp a piece, so thats all you miss out on if you take my suggestion and just get the hell out of there. It's hard to admit defeat, but you gotta know when youve lost.
I have killed a bunch of ´em allover the game first one was that Custard mansion thingy and even some in the wilderness, i just give them a "HIT AND RUN" manipulation, after all they are slow with that ice spell. I just dodge when they shoot, and then full speed ahead to whack ´em 
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Linear Mode
