Exlor
As a novice writer enthusiast, one of the toughest and most mind numbing processes is the research that goes on in writing a semi-acceptable sifi fantasy novel like this or any other novel that has to be historically and scientifically acceptable i.e. I have to give major props to the writer or his research team if he has any, for all the details given... I enjoyed the world building going on relatable details. Congratulations and thank you for the wonderful story.
I think the Red Cabal may have ties to local aliens. While it is possible they moved there just to get more power, if they are able to reach any massive concentration of spiritual energy within tens of millions of light years, they probably did not pick this one at random. It may even be the case their allies provided them with a beacon or something. If that is not the case, local aliens would not show up within a timeframe relevant to the story. Even if they detect the galaxy arriving in an instant, thus breaking relativity, they are unlikely to also teleport over instantly without having local support, since they would have to scout the situation first. And instant teleportation is probably demanding, as well.