I just wrote an absolutely massive post and lost it all in a power outage as I was about to hit Post. That is so upsetting when that happens.
Anyway, the conclusion I reached at the end of the post (I was analyzing the last two chapters and breaking down my train of thought) was that the previous agents of Heaven were likely killed by whatever killed Rider, so they never got word out of what was happening. Additionally, the Heavenly Host (who could actually turn the tide of battle) just sits there at the edge of the mortal realm waiting for a call to battle from the Source that they will never be able to hear (apparently 'that which was left behind' is interfering with the standard powers of Heaven in the mortal realm). I've always wondered with all these demons around where their counterparts were. The previous books once mentioned that Angels and Demons would fight 1:1 - when demons invaded the mortal realms, the same number of Angels would show up to defeat them.
Apparently the rise in power of "that which was left behind" has shifted the balance in the favor of the Demons (somewhat intentionally, as I believe "TWWLB" wants to cause chaos, hence why he was intent on destroying all the 'civilized' demons). As for the potential identity of "TWWLB", I believe that it COULD be the Dread. I honestly hope not though because with multiple Dreadlords being defeated in the series already, it just feels really dumb to have them as the 'super ultimate enemy' to end the universe with. I hope that it is some ancient power that is behind the Dread, or that we don't fully understand the Dread correctly. Hopefully the power in the Demon realm is not just another Dreadlord (why are they so vastly varied in power?) and is actually the same entity as "TWWLB". Possibly there will be a revelation that the Dread has always been one entity, but that it was mainly mindless in the past because not enough of it could enter into the mortal realms at once to gain the intelligence needed.
Anyway, there are tons of possibilities for that, but there is hope for a good final book from this scenario. I just really hope he doesn't spend half of the final book on trivial **** like one single Dutchy fighting a handful of Keshian Soldiers. Because the readers understand what is stake, you can't just go from Angels and Demons to a brawl between some of the most puny humans alive over a city that doesn't actually matter. I'm okay with the very beginning (even up to the first third) finishing up the Kingdom stuff - make Hal King by getting Stephané on board as Queen, which makes his claim the best - but then it needs to move on to the overall picture.
Also, while I really, really liked the A Crown Imperilled, the editing mistakes are just completely unacceptable. I will accept a misspelling here or there (as long as they aren't misspellings that Microsoft Word would pick up... I mean seriously), but these were far from trivial. I saw three that were glaringly obvious (two completely mangled sentences and then the Pug/Magnus switcheroo on the island), which makes me think the editors are either nonexistent (as suggested above) or entirely incompetent.
TL;DR: I cross my fingers for the next book and pray it ends well... it definitely has a good chance if done right!
Edit:
Even if he is still around and the cause of what is happening now it is going to feel like a 'oh yeah, I haven't mentioned this guy but he is the cause of it all' feeling.
One theory is that the Panthanians, Sidi, the Nameless One, the Demons, and (possibly) the lesser agents of the Dread all serve the same purpose and cause ("TWWLB"). However, most of them are unwitting and don't know that they are being played to advance another's goals as well as their own. They've repeatedly referenced that nobody knows why the Nameless One went mad (and assumingly caused the Chaos Wars), but that second to last chapter even had Rider (who is merely an agent of Heaven) refer to the "gods" as lessers. The Nameless One and the other Gods only know what the mortals know (by definition of a god in this universe), so they can't know that they are being manipulated when nobody else does either.
