one of the things i absolutely loved about star wars: kotor 1&2 was the continuous development of your character depending on your choices towards three alignments (dark, light, neutral), which were further distinguished in "lawful", "chaotic" and "true"
this could be adapted on the empire level for example during the exploration phase, for the policies you pick, for how you fight wars, if you're using the colossus, how you treat xenos, how you respond to diplomatic offers etc.
leaning towards a side would grant buffs, towards the light side might gradually buff your ships' defense and hull points and make bastions stronger, the dark side might come with buffs to your weaponry and also unlocking new weapons, and neutrals might be rewarded with a flourishing economy
lawful empires would get random events with positive outcome (happiness, stability, leader skills etc.) as a reward for staying true to the alignment you pick while chaotic empires would see their unrest increased and so on because you would make erratic and impulsive choices, not actually following the moral alignment but rather the situational profit
it would also affect the appearance of your pops and leaders and the dialogues in the diplo screen, just for the flavour and nicer optics (it feels anyway to meet that cute little creature with deep dark eyes and an almost smiling face... who happens to be a fanatical purifier wanting to exterminate your species)
(or why the authoritarian advisor always sounds evil even if you're the galactic emperor declaring the eternal peace and defending the galaxy against crisis forces, while pacifists sound like saints even if they're inwards perfectionist and purge every single xeno they stumble upon by extermination)
any opinion on that, or other ideas?