"Escape to Salvation" - "Magnificent Retreat" [Campaign 4, Mission 4]

I haven't upgraded Frida, please tell me which mission I need to complete to upgrade her... thank you in advance.

Added after 9 hours 42 minutes
people, please answer my message!!!

Replay the second part of the second mission - in my opinion, the optimal development is as follows: Darkness (you must have "Vampirism," "Domination"; it is desirable to have "Blindness" and "Berserk," but you can do without them), Defense. The rest is up to you.