I still cannot defeat uber Atziri after these 3 years

use a warchief totem as a friend, or a spell totem with wither or just level up a marauder with ancestral warchief totem build and kill evrything with 3-4 ex budget.
u can also go dualwield if ur problem is to kill the copies, can I ask u what's ur dps?
I would go with concentrated on copies instead of critical damage.
Anyway mate, gl, ur drop will be a shining vertex but if u wanna kill her for ur personal satisfaction, well, u re close to achieve ur goal, don't give up.

use a ruby flask with increased duration instead of kiara's.

yeah mate ur average damage is not bad but not either good, u don t use hatred if u can manage the mana res u could drop vulnerability using the witchfire flask. but try even a totem as backup, wc for dps wither for slowing at least the one who throws spares...

What was hitting you in the split phase? Take and charge up multiple Vaal discs, and pop one before each split phase.

You need to understand what is killing you,this is from wiki
(Atziri Third form
One holds a spear in her hand that fires a single projectile at the player; dealing bleeding damage over time.

One has fire on her hand and casts a single Flameblast on top of the player's current location (Similar to first form's single flameblast).

One has lightning on her hand and casts a chain of randomly placed Storm Call

One has a mirror and reflects a high amount of damage. Attacking this with direct damage is fatal and is only an option for characters that deal indirect damage.)

So you are either dying from bleeding after spear attack or hitting the atziri with the mirror(She has reflect)
So if it is bleeding take antibleed flask if it is reflect dont hit the one with the mirror

I hope this helps

It's a mechanical fight though. [Removed by Support] you'll figure it out.