I did it! 7 star thrawn! All gear 8 Phoenix with chopper. Only one omega ability. The rest were level 7. All Phoenix were only level 72 to 85. I lost hera and kannan, but won with the other three alive. No zetas.
It can be done to those who are discouraged!
Disclaimer note: may take 500 tries. Loss of sanity is not 100% avoidable. Broken phones may occur.