As to what your saying that we can't trust Akka. We know through him that he has gone over the records of the dreams, discussed dreams with other Mandati and knows the type of differences that are experienced. I do take it reliable, I guess that's were we're disagreeing.
It's not that I don't trust him, it's that I think some key pieces of information about Seswatha's Dreams are deliberately withheld in the narrative. For example, people might have been seeing mundane Dreams from time to time, but not cataloguing them diligently, thinking it's a fluke. Or someone might have seen a contradictory Dream, like the one with the Heron Spear missing, and not mention it at all, considering it not a real Dream. Like, the person seeing it was tired, or upset, or delirious, or any number of other reasons to not put much stock into his dreams.
If only there was some discussion about how different people live with Seswatha's Dreams, what they see, whether they try to influence the dreams or not. But there isn't one. We have Serwa, who is, surprise, Seswatha every single night, and all we get from it is a mention that she has some experience with the Amiolas. And she is a woman, which in itself is interesting, because before the Swayali only men saw the Dreams. But she's not just any woman, she's an Anasurimbor, half-Dunyain, and a Metagnostic sorceress to boot, who was instructed by Kellhus himself. Yes, that prodigious superhuman sorcerer interested in Seswatha's Dreams, which is further evidenced by him incorporating the Grasping into the Swayal Compact. His daughter sees the Dreams, and then we never speak of it again. To me that looks very pointed. There is something there, just like there was something with Kelmomas, and then with Kellhus himself in relation to Ajokli. I can only surmise it's of importance to the third series, so no spoilers on the Slog.
Yes has the first of them in TJE and WLW were he is a toothless wretch being dragged in a line towards the golden room, that's Nayu.
Was that before or after Achamian starts taking Qirri?
I'm also completely in agreement that the wretch in the line to the Carapace is Nau-Cayuti. By all means it should be him.
Another bit of textual evidence is his scene with Sacareess in TUC when he asks if his dreams have changed and he says (Sacareess) no, just intensified. And Akka says that his has in a whole different way and Sacareess wants to know and Akka denies him. Plenty of proof that what Akka dreams when they change is nothing like any other Mandati has experienced.
That entire scene just aggravates my suspicion that some key pieces of the puzzle are not presented to us. Here is a perfectly good chance to have a discussion about Seswatha's Dreams, but there are so many more important concerns no one is very inclined to take the time, and so we get no insight. Sacareess in this scene just seems to me not interested in Achamian at all, wanting to get rid of him as fast as possible. Can't really blame him, he has many pressing issues at that moment, but it's very suspicious from the narrative point of view, considering the importance of Achamian's dreams to the story.