He is not bugged. Just a huge curve of difficulty compared to all other fights.
As far as lightening balls, if someone is slow to react they can get "shocked" more than once by a ball, and then if it blows up, that person will die. Awareness is the only solution here.
There is some RNG to the fight like getting thrown up into the air and being brought down on top of balls (especially in phase 3), coming out of mind trap on top of multiple balls, and having your tank mind trapped. Those are just part of the fight, and can usually be over come if they are your only deaths.
I figured it could be covercome if we had more time. But raid ended at 12 and we started a bit late, alot of time having pylons glitch out on us and not spinning when the button was clicked. However could 1 of the big issues be that we are all in mostly champion gear? Some of us may have 2-3 pieces of gear but generally its all champion/centurion.
The problem with BT is we tried getting someone to go in first, but after we all went in it reset him and he swiped us for all our health regardless.