This is one tough fight.
You must have enough shadow protection and health/mana to outlast his initial damage: mind flay. Once you have done this you must have enough mana regen to heal faster over time than his damage.
He uses mindflay, shadow word pain, and physcial melee. His mindflay hits for 1500, shadow word for 225, and his physical hits for about 350.
Ideally this fight requires 200 shadow protection, 5000 health, and 5000 mana WITH good mana regen. The guy in the video has a full lawbringer set. I know Vorlon has killed him with a full judgment set. I have to piece gear together an armor set for this and I end up short on health, with about 3700 health. Therefore, the first part of the fight is tricky because if he hits me for 2 mindflays in a row I am toast
I have gotten through this first part of the fight but I was low and ran out of mana. This is even using major mana pots every 2 mins

It is a tricky fight to be healing, cleansing, judging wisdom, hitting seal of wisdom often, using your shields at the right time and bandaging, using your crit heals, and drinking mana pots. With my narrow margins, if I fail to do any of these I am "You are dead".
I think I must either get better gear or get lucky that my heals are crit and his damage is not. I think the pally in the video wins almost every fight, not an occasional fight

I am not even close to that yet
There is a 5 man quest in blasted lands to kill a demon that will give me a trinket and a neck piece with shadow protect. I may be asking for help on that one next week
Kevin