As stated in the topic. maybe one of the late game events is ware the fallen empires ware at war with one another at one point and it is heating back up.
I do like the idea that we where a FE that was sent back to the stone age and forgotten about by everyone and maybe we are on a quest for revenge.Wouldn't have more sense, if we are one of the two?
By late game, we should be puppeteer of empires and federations... doesn't this make us the Vorlons/Shadow? And one hairless ape could deliver a terrible speech to force us to leave... and we could crush that insolent worm...
Paradox are also considering something involving the game’s fallen empires, the classic trope of the decayed super-species that once ruled the stars but now only have a handful of worlds. Either one of these races will decide to kick themselves back into gear and come charging out of their peaceful regions in technologically superior ships - or two will, going to war with one-another over ancient feuds, with you and any other cowering mortal races rather stuck in the crossfire. - Source
Q: Can you wake them in Stellaris?
A: At the moment, no. I'm 99% sure it'll be added as a potential galactic 'disaster' sooner or later though. - source