100 Ranger here with 91.5k hp 20min fight. At least 10million hp. Be ready for the poison it will drain your mana slowly. I had a merc up to start the fight but he went oom and i let him die. I had to use Staunch recovery, I went oom when mob was at 25percent (67.8k mana). 4k aa's. I Also used my Steadfast servent. Lol it dropped 3 Fabled Mask of the Insightful + 1 regular mask of the insightful. My weapons are Fused Coral Knife x 2 they proc a 306pt life tap and with my aa's i get crit heals for over 1700hp. I dont think i could have defeated this monster with out all those procs.
Well, My mage and my necromancer (both lvl 90) tried to duo this monster and just couldn't take her. No spell I cast on her would land so it just became a kjlkj pet fight which lasted for 20 minutes before both my merc clerics were out of mana. Let me know if you find some winning strategy on it. It did seem that the fabled poisoned flames were directional so keep your pet focused at least at a 90 degree away from you.