Been a while since I watched the intro video, but it starts with a screenshot of an...
Experimental Transport Lab
Which to me would suggest they were experimenting with manipulating phase space.
The third scene shows a lot of energy being released and striking what looks like asteroids
Is it possible that it isn't an enemy per se', but they've somehow destabilized the galaxy itself? or perhaps space/phase space is collapsing because of what they did?
Maybe that's their sin, breaking "space", heh.
Seems like they'v ebeen on the run for 10,000 years, which seems odd, in that time, they should've advanced a heck of a lot more than they have (I would've thought)