Sorry if I'm spouting garbage here but its been a while since I've read the books and while I was checking for an update on the next installment said I'd check out what the ideas were for wtf is going on.
Lots of garbage floating around here, and a good portion of it is mine, so no worries there

Welcome to TSA.
As far as I'm concerned what Kellhus is doing seems political but for uncertain ends possibly with the control of the consult in the balance. IIRC Kellhus had a negotiation with the Nonmen. Now where did these non-men come from and what are their goals? Didn;t Kellhus have a conversation with "the last Nonman king" (can't even remember his name now)? who said that the last fortress of non-men had decided to turn to the dark.
That conversation revealed that many Nonmen fight fro the Consult, and that nothing goes on in Ishterabinth that the Consult don't know about. The envoy, whatever his name was, didn't say explicitly that all the Nonmen fight for the Consult.
Kellhus seems to believe that they flew on their fiery chariots from Ishterebinth to him, but I suppose we don't know that for sure.
Assuming the non-men are now part of the dark side or allied to the consult this means Kallhus has promised to take a fortress back for them which has possibly been overun by the Sranc and more interestingly there may be factions within the Consult that have infighting and by returning the fortress to the non-men Kallhus gains their alliegance and gains more influence in the Consult.
I don't think there will be many Nonmen within Dagliash, though it almost certainly is overrun with sranc.
We have had no indication that there is any infighting within the Consult. They all, meaning Aurang/Aurax/Shaeonora, are all striving to save their souls by sealing Earwa off from the Outside.
Nonman make mercurial allies. They seem to flip sides whenever it suits them. Mercenaries to be paid with the coin of atrocities with which they can make memories. Kellhus is likely trying to convince them that he will be the winner of this war with the Consult, and thus turn them to his side. The last thing he wants is a cabal of Quya showing up and trying to kill him.
Assuming this is true then it would be fair to say that Kellhus wants control of the Consult, why though? IMO to resurrect the No-God of which he would then possibly have control or even become. This could be the reason for infighting between the consult as none of them can agree who is to ascend. At the very least he may have a belief that resurrecting the No-God would stop him from being damned.
I can see two paths here for Kellhus, depending on what he truly is or what his motivations are.
Path number 1: Kellhus is a Dunyain.
He wants nothing but to dominate all circumstancts. Like with the Holy War from PoN, he found that unless he controls everything, he himself is being controlled. In order to be a self-moving soul, the Dunyain's only purpose, he must control everything. Women, Men, Nonmen, Consult, and even the Gods. The Consult are just part of his plan, and he will use them to transend the cycle of before and after.
Path number 2: Kellhus is not a Dunyain.
Kellhus is fighting the Consult to save the world. He has decided that in order to do this, he must stop the Consult from sealing off Earwa from the Outside, which involves the wholesale slaughter of nearly every Man, Woman, and Child. This is unacceptable to him, and he seeks to destroy the Consult.
There are a few possiblities as well that cropped up in my mind first among them is that Kallhus is Shaeonanra either resurrected or suffered temporarily from amnesia. It would explain why he had a Father if he was reborn. It may be that Kallhus up to a point had no idea who he was. As of yet Shaeonanra has seemingly had no direct involvement in the events in the books. From what is mentioned of his ability and power it seems like he single handedly could destroy the entire "crusade" other than Kallhus of course.
Interesting idea, but I don't see much support for it in the text.
Also, I don't think anyone, even Kellhus, could solo destroy the Mandate and the Swayali. The Consult will need something far more powerful than brute-force sorcery to take them out. Shae is powerful and intelligent, but I doubt he is stronger than even a handful of the Gnostic school(wo)men, let alone the fact that there are at least 2 meta-gnosic wielders not counting Kellhus.
Maybe the Dunyain are related to the Consult as the whole logic and end goal thing really seams eerily similar to both.
The Dunyain have been shrouded in mystery since the beginning. We are going to learn a lot about them in TUC.
Also if Kallhus is Shaeonanra and has been reborn several times it may be due due to this that he has memories of a Dunyain upbringing.
Not likely. Shae is absolutely terrified of the Outside. In my opinion, he wouldn't risk being reborn for fear that his soul would get stuck in the Outside.
Of course there is the possibility Kallhus is the No-God's avatar and again did not know it up to a certain point. This would make some sense given the deficiencies of his children. Also his apparent lack of emotion also is similar to the No-God. Heck Kallhus could have taken over the first crusade to look for the Heron Spear and remove it as an obstacle.
The idea is possible, and many people think that Kellhus is/will be the new No-God. I just don't see how birth defects in his children or lack of emotion are clues. His father also had defective children, so it is far more likely that this points to something strange with either the Dunyain blood, or more specifically the bloodline of the Anasurimbor's. As for emotions, again, none of the Dunyain seem to exibit many emotions, and on top of that, the No-God showed us nothing so far except questions, it may or may not have emotions (hard to say either way with its own POV).