For this achievement you need to cover whole galaxy with your zone of influence.
Best settings for this game is 4 empires (you as Nakalim, then i recoment Lumeris, Hissho and Sophons) also you want many minor civilizations
At the start you need to bult as much exploration ships as you can because you need to collect as much relics as you can for your research
Also dont colonise every system colonize systems 4+ or if that system have some resources you really need (you need small systems for later in game)
You want to have good diplomatics with lumeris for trade and aliance
Hack academy for points on counselor heroes for your systems and give them relics for influence
bult every building for infuence and cover whole galaxy with your influence
then you need give them to academy (you need have temples on your planets)