I have no issues with the other Destiny fights. I feel the mechanic tweaks on those are interesting and challenging.
However, the Mithrelle fight is long, tedious, boring and serves no real purpose, except to test if you are a DPS class or not.
I fought her with my Guardian, and no joke, the fight lasted 14 Minutes, 29 Seconds. If you are a healer or a tank, this fight is utterly and completely miserable. Fight for 3-7 seconds, knock off 1% of her health, 2% if you are lucky, get tossed out of combat range, get stuck in place for 3-4 seconds, then run back and repeat the cycle until she is dead. 14 minutes and 12 Health Pots/Stamina Pots later, I finally killed her.
The fight feels about as epic as trying to kill Godzilla with a dull spoon. Oh, and for the record...constant, uninteruptable knockbacks on a schedule? Totally not the express lane to cool.
Devs, please, I beg you...redo this fight! More mechanics and cool factor, less HP storage tank.
PLEASE!
(Added as a short line to the Suggestions thread.)