Another thing is (at least to me), as far as I know we're never actually given a solid reason behind why their Creational magic started going AWOL, and you can't try and tell me they wouldn't have investigated it as much as they could. There's mention of the laws of the world unraveling or whatever, sure, and it's entirely possible that it IS just some kind of 'natural' occurrence, maybe they exhausted some kind of fundamental resource after thousands of years of creating things from pure aether, who knows.

But i'm pretty sure it's been mentioned, or heavily implied, that the issues started basically on the other side of the world to Amaurot, basically in a somewhat localized area and then slowly spread out from there. With Amaurot itself being one of the last to be infected. Seems suspicious to me. If it was something natural, I would expect it to start off or spread more randomly, with cases popping up just about anywhere.
But if it was engineered, then it would make more sense. For one thing, just because the Ancients had to sacrifice so many to effect changes to the star (though they were rather serious/fundamental), doesn't mean something from outside wouldn't have the power to do so by itself. Hell, that's assuming it's even a single entity instead of some kind of collective. It's a big universe after all.
Also, at that point, our star was basically a 'virgin' star, with no will or maybe something very basic, so I assume that would make it easier to make changes to. And the beauty of it is, you wouldn't even need to make any major changes; just affect that one area so their magic starts going crazy and let the Ancients fear and doubt finish the job for you. After all, we know how easily stray thoughts can change the outcome when someone's Creating something. As long as you had the one area where everything was assured to go wrong, the surrounding areas would start wondering if maybe their own magic would start showing similar issues and slowly spread out from there.

As for the Ascians joining forces with us/redeeming themselves, considering that both Emet-Selch and Elidibus have felt the need to 'reevaluate' us, I definitely think there's room for some kind of cooperation or dialogue in the future that doesn't involve us trying to murder each other. And definitely hoping Emet makes a return of some kind regardless, cause that man gave me feels. Not too sure what i'm expecting of Zenos though, I'm kind of wondering if Elidibus is hoping what's left of Zodiark will take him over and gain a physical form or something. You know, that's not a dead rock in space (presumably). Elidibus also mentioned how the flow of history is slipping beyond his grasp or something to that effect (I can grab screenshots later if anyone wants), so almost tempted to think he's just throwing a bunch of different plans around and seeing what sticks haha. Or maybe they're 'tests' for us, similar to Emet making use of the Lightwardens.