The Invincible

You need to take the alliance field base path earlier in the story to gain this achievement, do not take the path to the lander.
After taking the alliance field base path you can then get to condor and head to the top floor with Rohytra and select the dialogue below:

At the bridge go through all the dialogue with Rohytra selecting whichever you want, ideally being in agreement with the bombs until you come to the Necroevolution theory. DO NOT choose the 'Necroevolution theory [discussion]', instead select 'There's no point speculating'.
Now when Novik asks if you agree about them being invincible select 'There is a chance of success, but it's small.'
Rohytra will then ask if it's worth trying with smaller charges, select 'It won't hurt to try'.

After the remaining dialogue you can activate the launch control switches and you will find out the cloud didn't die so now is the time to escape. After more dialogue head over to the controls to open the dome and then make your way up to the landing pad.
You will find the dome controls near to the radio transmitter where you spoke with Novik when you first entered the bridge, look for the handle that's in the downward position on one of the computers.

At the landing pad grab the hatch handle and at the next dialogue select 'I was supposed to wait for Rohytra' and just stand there and wait, do not touch anything else and you will be consumed by the cloud and gain this achievement.

If you need more help with this you can follow my video guide below, it will start at this achievement: