Well, if you want to actually straight up fight the boss as they intended, and not exploit it, that's the easiest way I've found, but then I get two-rounded and die anyway. If grunts are around it's not too bad, but I kept dying with none in range. You can however exploit the hell out of the fight and take no damage if you really want. I don't like cheesing bosses like that, but I'm reaching a point to where I feel like I need to. I feel severely ill equipped for this fight, yet it's a progression boss so I have nowhere to go to "farm" better gear anyway.
I've done it once just to see if it worked, but I haven't been using it really myself yet since not only is it tedious, but you wouldn't really want to do this until level 50 anyway, if you were going to do it. Unless you're just stuck with no upgrades...
Except that's not what I am doing. You can run to the side of the ice shit that travels the halls, but how do you avoid the five orbs that explode and puke lava everywhere? Tried shooting them, tried shooting his generator, and they just stay up until they eventually blow up. Staying in the halls magically causes those (the tracking) orbs to blow me up anyway and running around the map does nothing either. It just prolongs the fight. I've consistently gotten rid of his shields by staying close, while I've done nothing but die at range. And in case you missed it, I can't hit adds that aren't near me. They are usually camping in the halls, and only occasionally drop down into the pit.