Assuming we are not talking raid version, since I have not done that …
I stuck with the center skill tree mostly and a few off of each of the others.
Spamming shock transfusion gernades and a lvl 60 Moxxie’s Vibra got me through. It is not a sure thing, but doable more times than not. I also have a variety of other nice weapons, but seem to always need the health off of the Virba so it seems to be in my hands a lot.
A lot of hiding behind the pillars and hoping the guardians are there for 2nd winds.
Don’t shoot at the Sentinel while bullets are being bounced back (twirling the staff thing), or while rising up and immune (wastes ammo), and dodge the novas.
I go ahead and throw the shard. I dunno if it hurts the Sentinel, but it can get health off of the guardians around the area.
I believe it has to go through the 3 shield depletion phases. I don’t think there is any way around that, but maybe I missed a video where someone has.
Yeah, the Empyrean phase seems simple compared to the first. The first can just slap me down like a bug.
Really a lot of builds, info, and videos from better players than me here. Check 'em out.