I was able to solo everything in ZA except for the last boss, until recently, when i was finally able to solo Daakara the last boss. Nalorakk and dakaara both have that surge debuff, they do hit hard as a mother truck, but its totally doable with good CD management and smart purifying brew usage. I do nalorrak and only really use fortifying brew, but for dakaara you need EVERYTHING.
Nalorakk just watch for the BRUTAL STRIKES (thats whats hitting u so hard) and purifying brew the second they hit you, and immediately start healing the damage, make sure you have shuffle up otherwise you wont be staggering enough of the damage. He does a ton of damage it will be hard to keep up but yea easily doable. (he will do a lot of damage in bear form also but theres no brutal strkes, just keep shuffle up, purfying brew when you get hit hard, and then big heals.
Dakaara is Nalorakk on steroids, he consistently has 200k+ hitting abilities you really have to watch the dmg you take and purify smart, heal big, and try to keep shuffle up when your going to need to stagger, its not easy but yes, its doable ( i just did it like 1 minute ago for the third time solo).
Ultimately you just have to be really smart with what you use your chi for, you will actually become a pretty good tank learning how to deal with damage that no other class can really eat on these fights.
You can do it without this trick, but i found a good way to avoid a lot of damage when doing these: Spec for glyph of retreat, Xuen, and Celerity. and when you start to feel like too much damage is incoming, pop Xuen, roll, and he will tank for you because your threat is at 0, you can keep rolling as long as you dont want threat, with celerity Xuen can tank Dakaara for like his entire duration its pretty nice, NOTE: dakaara is not going to do bad damage until he goes bear form (IF he goes bear form) and puts surge on you. Good Luck! (those damn shoulders off dakaara have yet to drop in 15 runs,
(( )
ALSO spec dampen harm, to nerf some of those massive hits when you really need it.
With the xuen trick theres not really much skill involved anymore lol he does all the work and you just dps and occasionally heal the surge damage xD