Just a video of a kill me and my guild did on Elegon ages ago.This one won't be a guide since the content is getting old, but if there is interest I can add some information about what I think is worth thinking about when healing this fight as a discipline priest. Questions are always welcome of course.
Overall I am not very fond of this fight, I find it one of the more boring ones to heal in MV. There is a lot to heal admittedly, it's not boring because of lack of challenge. I think it is because it is pretty rinse-and-repeat in style, redoing the same thing over and over. I usually prefer the fights that require more of a quick think and reaction style of healing, maybe with some running around. This fight is quite stationary and timing of cooldowns and mana management are the two challenges here (although that goes for most fights). As a healer there isn't much to think about except that, and it gets kind of dull after a couple of wipes.