Working my why through the Prologue. I always entertained the idea that the Bardic Priest could have been part of the Consult, but there was always something that didn't fit right about that. Mostly, that if he was, how did the Consult not know of Ishuäl sooner then? Indeed, this is not proof, as we cannot ever
know for certain if he was or wasn't. I think the balance of plausibility leans toward him not actually being of the Consult, but rather a symbol of the moral (and maybe ethical) decline at the end of the world. Not only that, but his framing, as a Bradic
Preist, emplants the idea of a morally corrupt religious order, again, framed against the end of the world. This is definitely evocative of a certain level of "Christian mythos" in the sense that the declining moral fiber is a sign of the End.
As for the latter part, with Kellhus, apart from the oddity of the whole endeavor (as in, why was
Moënghus not in Ishuäl in the first place, why would they have risked allowing him or Kellhus to be out in the wild) is abut the role of the Logos. The Logos (Biblically, the Word that forms Order from Chaos) is what grounds Kellhus, what the Dûnyain had used to master circumstance (and themselves and so their world) yet leaves him completely overwhelmed by the Choas that is the Wilderness. Kellhus nearly dies attempting to figure out the pattern, discern what it is that he is seeing, logically, in the wild. It's only once he finds the ruins, does he "return to himself" in a sense, seeing his own reflection and his wild visage, reawkens in him the words with which to tame the wild (both internal and external). Kellhus no longer meanders in the wilderness now, he runs, because he realizes it is not the proper state of his being, it is Chaos.
When he meets Leweth, the depth of the Logos becomes clearer. It isn't just "logic" as we'd describe it. Leweth displays the order, "Each thing had its place, he would tell Kellhus, and those things out of place portended disaster." but fails in the fact that his evocation of Order is not Truthful, which Kellhus later unmasks. This shows that the Logos isn't just "cimply" order, but is Truthful Order, the proper and factual ordering of the world. And it shows, through his breaking of Leweth, that the Truth (and so the Logos) has
power.
The Sranc and ensuing death of Leweth point to the depth of the Chaos that is Eärwa. Then, culminating in the encounter with a Nonman, we are presented with the
fact, yes fact, that the Logos is not all that there is. This will actually be returned to much much later in the series, as PoN is really Kellhus (and The Logos) ascendant.