First of all, welcome to the forum.
While I still found many things to enjoy in TUC despite the disappointments, I can understand where you're coming from. All the ambiguity in this last book can be quite confusing, especially for people (like myself) who haven't reread the whole series several times. Not sure if that is your situation too.
1) I never thought I would see a Deus Ex Machina (god in the machine) used by Bakker to conclude a book. There was literally a God (No-God) in the Machine (Carapace which was described by the Dunyain as a prostheses for Ark). Notwithstanding the other God that shows up (Ajokli) with no set up.
Well, the return of the No-God had been present as a possibility ever since TDTCB, with the existence of the Mandate, the Celmomian prophecy, etc. Opinions may vary if it was properly foreshadowed throughout the series (particularly in the more recent books), but if you look carefully, it's there. I'm currently rereading the series for the first time and I've already noticed quite a bit of foreshadowing concerning the No-God in PON alone.
2) Serwa described the Consult as possessing no more ferocious souls in existence, save her Father. We see Aurang taken out within a couple of paragraphs (Kellhus' battle with Meppa was more fulsome). Aurax seemed like a beaten dog (don't know if he was always like that or just beaten into submission by the Dunyain). Mekeritrig was knocked out instantly by a magic lasso. Shauriatas was written out of the story with a sentence. The conclusion of the book felt like things just ran out of steam. Perhaps if half the book wasn't spent describing sodomy, rape, cannibalism, necrophilia, and general leper licking and other fun acts, there could have been more emphasis placed on a more refined conclusion.
3) Speaking of Shauriatas: he was the Archidemu of the Cunning School, took out Titirga through trickery (the legendary Hero-Mage who was possibly the most powerful sorcerer ever before Kellhus), Cheater of the Gods, figured out a way to penetrate the Artisan's glamour, overall evil genius par excellence, etc. And he didn't even make an appearance because he was taken out off-camera because they were dumb enough to bring, not one, but five Dunyain into their keep.
4) Speaking of the Dunyain, the Consult had a healthy wariness of them considering, you know, everything that Moeghus and Kellhus were able to achieve, being provided with intel by Cnaur, and probably having access to Achamanian's unauthorized biography. Kellhus, when Aurang possessed Esmenet, saw that they FEARED him because he represented something new to their hoary souls. Heck they went through the trouble of finding and destroying Ishual. I find it beyond implausible that they would bring 5 of them to Golgotterath to brainwash them to their side.
I absolutely agreed right after finishing TUC, but I've had some time to think about it afterwards and it seems fitting to me that the Dûnyain took the Consult over. It's still a shame that Shauriatas died offscreen, and that Mekeritrig died so easily, I really think that was a waste of both characters (especially Shauriatas, since Mekeritrig did get that short scene at the beginning of TDTCB). I don't feel so strongly about Aurang because we got to see him as a character plenty of times before this (again, it's a matter of opinion here). Aurax, well, it's not like we knew him prior to TUC - who's to say his current state was just caused by the Dûnyain? His mind and personality might have been deteriorating for a long time and there's no evidence to say otherwise.
I believe the reason they ultimately underestimated the Dûnyain despite their wariness of Moënghus and Kellhus in PON was their pride. They still believed themselves powerful enough to overcome the threat of the Dûnyain, and so they didn't completely exterminate them and brought those five as prisoners to Golgotterath. Probably hoping to debase and demean them with torture, rape, etc. to show them (and themselves) that the Dûnyain weren't so mighty after all, that no matter what Moënghus and Kellhus might have done out in the world, the Consult was still able to deal with the Dûnyain. And in that they were undone.
As for the Great Ordeal sinking into depravity further and further: I agree with you, that part of the book should have been shorter. No need to fully remove it, just trim it down a little.
5) It also seemed somewhat silly that the Consult, considering how smart they were, couldn't figure out how to activate the No-God. You'd think they would just refer to the last and only time they were able to activate it...you know the time they tossed Nau-Cayuti in, and extrapolate from there. Guess they should have kept better notes.
I'm still unsure what to think about this. We really doesn't know how exactly the whole process works. It could be much more complicated than it seems, they could have thrown in more people along with Nau-Cayûti and weren't able to work out the variables, etc. Even if they did figure it out and what was needed was indeed a person of Anasûrimbor blood (and we don't know this for sure), who would they have used after Celmomas died? There was no way they could have known about Ishuäl, and as far as the rest of the world knew, the Anasûrimbor line ended with Ganrelka.
Of course this doesn't justify not trying to get to Moënghus/Kellhus after they learned of their existence 2000 years later, but like I said before, we're not sure how it works and I was going on about a speculation here (maybe someone who can explain this better will contribute their thoughts later).
6) Then there was the question that has been lingering since The Judging Eye - what would Mimara see if she looked at Kellhus with the Judging Eye (seemed that was the whole point of Mimara and Acha's journey). Nope, that didn't happen did it? Conveniently, we get a sentence describing how the Eye just wouldn't open.
Mimara has never been able to get the Judging Eye to open when she wants it to, it has always been involuntary since the beginning of TJE. And she ended up not being in close proximity to Kellhus for that long, anyway. When she lived in the Andiamine Heights, she rarely saw him. In TUC, she was taken away by Esmenet when she went into labour. By the time she gave birth Kellhus had already gone into the Ark. And if you remember, she and Achamian spent months travelling with the Skin Eaters and she saw them through the Judging Eye a total of...what, two, maybe three times? It may be convenient, yes, but not
that convenient when thinking about it.
7) Then there are things that just seem to break all the rules of this universe with no explanation e.g. Kelmomas apparently able to disrupt or outright banish the Gods from the world, e.g. Yatwer's White-Luck and exorcising Ajokli out of Kellhus by standing in front of him. Right.
Like Mimara, Kelmomas has had his special abilities ever since TJE. It has been theorized in other threads that him becoming the No-God made it so he would always be so in the eyes of the Gods (as time is not linear to them), and therefore invisible (again, there are people who can explain this better than me). It worked with the White-Luck Warrior and Sorweel as well because they were agents of Yatwer.
I don't think he exorcised Ajokli exactly - Ajokli was blind to him, so Kellhus "switched back" to himself to see what was happening, as he couldn't as Ajokli.
Then there are the general things that we probably won't ever get an answer for, which leads to the question, why were they even there to begin with, eg. somebody commissioning Kosoter to keep an eye on Acha during the Prelude of the Judging Eye, why the heck was there an eyeball in that Scalper's heart down in the Mansion, etc.
I'm guessing the eye in the scalper's heart was a result of Cil-Aujas being a topos.
It's possible that we will never know if Achamian and Mimara's whole journey was being controlled by Kellhus from the beginning or not, it was one of those things left ambiguous. It could be that way, but it's still unclear why he wanted them to be there (unless you believe the theory that Kellhus was reincarnated as Mimara's baby).
