> Can't be earned if pacifist, xenophile or Fanatic xenophobe (Autoritarian/Materialist works well)
> Needs Ironman (obviously)
Step #1> Start with a ring galaxy with minimum size, but put the rate of habitable planet to maximum (x5)
> Expand the fastest you can, Conquer every other player until your Science ship find a pre-FTL world of reptilian, whatever the age.
> The Ascension Perk "Imperial prerogative" (+5 worlds for core system) may be of great help, since you need to forcefully stabilize your empire while expanding like crazy.
Step #2> Once the pre-FTL reptilian world is found, now start the tricky game of waiting.
> if they're under atomic age, then take your time to research "Gene tailoring" Technology, which is needed for infiltration.
> > Once you have the tech', you'll have to enlighten them up to industrial age, then, use covert infiltration in order for them to join your empire.
> if they're at the atomic age or early spatial age, then you'll have to make sure they DON'T :
> > Erase themselves through an atomic world war
> > Evolve to FTL species
> > > Whenever one of the two possibilites above happens, then reload right away your Ironman save WITHOUT going back to the main menu, that way you may get more time to have the technology / infiltrate them, since those are random events.
> > > It can be good to return to the main menu of the game once in a while when you're roughly at the 25~29 of the month, since most events happens at the 1st day of the month and the auto-Ironman saves will be made in accordance to the last save made. That way, you may keep your auto save made before anything bad happens.
*** Spoiler - click to reveal ***That part is extremely boring/tricky and i personnally had to reload roughly 30 times before having the tech + the infiltration done.
Make sure to reload your save from in-game, else you'll overwrite your save!
> Once the covert infiltration is successful, you get the achievement.
That's all!
This guide is a quick and efficient way to obtain the achievement, but it can be completed through others means or during one of your casual games