That fly in the air is his greater curse debuff landing. You can remove it with the RGC spell or if you have purify aa you can remove it once that way. He will recast it every 60 seconds I think. I always hit divine aura right when Emp goes aggro and the DA will eat the first curse. Click off DA, pop every single one of my burn buttons, and Emp drops quickly. Not sure what else to tell you. Is your Ssra bane sword slotted with 2 healing augs? That should help with sustain while you have your divine avatar and other burn stuff going
edit: are you 100% sure you are fully removing the greater curse debuff? If not, that will completely gut your dps and then yes you will die quickly since you can’t proc your sustain heals. Also, keep ethereal cleansing or whatever the best HoT is, going the whole fight if you have to. Also pop exquisite benediction and all your heal AAs for the fight if you’re dying. Helps a lot.