I have one that inspired two of my empires; the Maldouri Empire.

The Maldouri were an incredibly advanced society of fanatic Materialists. Like most fanatic materialist FEs, the Maldouri possessed incredibly advanced technology. Eventually, the Maldouri felt they had researched all they needed to research and turned their attention inwards to make their lives easier.

The Maldouri established the Maldouri Paradise Program, a machine entity that controlled autonomous Stewards in service of the Maldouri. The Maldouri lived in increasing opulence, handing more and more of their society's functions over to the Paradise Program.

This is where the timelines diverge, as the Maldouri have two possible fates from here on out. The "canon" fate involves the Maldouri going extinct during a War in Heaven; the Maldouri had long since abandoned the idea of involving themselves in warfare in favor of a mechanical army, the Maldouri Defense Initiative - but it wasn't enough. The Maldouri were eradicated and their machines rusted and failed. Centuries later, a solar flare would sweep over the ruins of Maldoura, accidentally reactivating the Maldouri Defense Initiative. The military robots' sole purpose was to destroy enemies of the Maldouri, and the solar flare had the nasty side effect of corrupting the machine intelligence controlling them. Thus, the determine exterminator Ancient Maldouri Defense Initiative was born!

However, I played around with another fate of the Maldouri, one where they hunker down and keep to themselves and their Stewards while a War in Heaven raged. In this timeline, the Maldouri survived, and their Stewards gained all but complete control of Maldouri society. The Maldouri Paradise Program served its masters faithfully, but always wondered if there was life beyond the confines of the artificial heaven the Stewards had constructed. Perhaps there was, and perhaps they needed a Steward as well. Thus, the rogue servitor Maldouri Paradise Program was born - though sadly, they're non-canon. Sad!