I had to take all my 7* Phoenix to g9+ with full abilities (minus omega except Hera). I can't tell you how many times I tried and failed with gear 7-8.
This event is supposed to be very hard, and would not want it any other way. You will need to invest in your Phoenix more, learn how to play them and maybe have RNG on your side after multiple tries.
Just because you have Phoenix at 7* does not mean you automatically get 7* Thrawn.
This reminds me of the first 7* Yoda event in the past before it was nerfed. Enough people whined about that and it was made easier.
I very much hope that is not going to happen again.
