How to Get The Phoenix Achievement
Basically ensure that you’re well set up in space before letting the aliens in, you lose everything on earth when the Servants win.
When the Servants win, cracking the AA will take a lot of time. Take the time to completely win the space war before taking back Earth.
If you blow up all the Alien fleets and habs/stations, they will have 0 income and be unable to do anything at all (literally, they build 0 ships and stations).
so basically step 1 is be completely independent of Earth and able to defend all your stations before “losing”.
To take back Earth, you need to have a bunch of councilors with high command (3 or more at 25CMD) (prep them before you lose).
It is super super important that no councilor has ethical.
Because to take back Earth, you’re going to commit some warcrimes.
Build fleets of ships with full coilguns around Earth and bombard the shit out of core economic regions with high population (think, India/China).
This will tank the gdp/capita, I think the floor is $100 global gdp/capita.
When the gdp/capita gets super low, cohesion will drop by -0.1 per month, so you then need to wait like 8 years while cohesion drops to 0.
Once cohesion is at 0, start spamming raise unrest in the alien administration, preferably in China or India (whichever you damaged less) or even USA (I think the game remembers your old miltech pre-conquest, not sure though) until a breakaway forms.
Use your bombardment fleets to protect your fledgling breakaway nation so you can stabilize the economy (use direct investment) and build up miltech/military and reconquista the Earth.
Good Luck, Commander!
You can easily buy nukes with direct investment.
Believe me, doing it to the moment you get to trigger global crop failures will make next part much easier.
To do that you need to get average weather anomaly temperature below -4 c
That’s like 50 nukes or so