So for chumps like mortals, who view the series one episode at a time...this is super worrying. Imagine you are starting to read TDTCB, and you hear a bunch of readers who have already seen the end talking about how Kellhus took down Conphas. That is hugely worrying to you as a Leweth fan, because it necessarily means that Kellhus doesn't marry Leweth and live with him forever.
If they struggle hard enough and are proficient in the lost sorcerous art of the Googling, I'm sure their needs can be sated through inevitable Kellhus/Leweth Rule 34 fanfic.
I get that the Gods are a-temporal but the No-God stands outside eternity etc., but why does the mere existence of the Ark presuppose system resumption - and success? The only that this can make sense is if the Ark was destined to be successful since its inception.
Also, Bakker's reply seems to indicate that what Kellhus is saying is not that the Inchoroi literally must win.
Bakker's reply aside, this is more of the circuitous logic of temporal paradox we've seen relative to the gods and WLWs being blind to Kelmomas. The gods being blind to the No-God means it falls outside "eternity" (the gods' perception of time), which means it wins at some point (unless events in TNG find some other means, possibly through the "re-invention" of the gods in the wake of their blind spots, to so radically change the nature of connection to the Outside as to render the previous incarnation of "eternity" irrelevant).
Given the gods' remaking in the wake of events consummated within their blind spots, it may not amount to anything. If Khellus had successfully destroyed the No-God, it would have no longer fallen outside eternity, and a new version of the gods that were and
had always been aware of the Consult would exist. (Confusing, I know, but that's atemporality for you.)
I think the broader point to take is, under current framework, the No-God is destined to win, but that the deterministic path the universe is on
can be swayed within the blind spots of the Gods. Perhaps Achamian pieces this together with the mighty Likaro and they find a way to engineer further divine blindness, exploiting it to rewrite the future as written by the darkness that comes before.
It could also be that Khellus was speaking, in a roundabout way, of his
own plans, and whatever his grand vision, it required a temporary Consult victory. Bakker has repeatedly stated Khellus is dead, though that could be a technicality (perhaps he's "dead" in the same way as Malowebi?). He also said the Thousandfold Thought only extended as far as the Ordeal reaching Golgotterath... though I do recall him saying Cnaiur was dead and gone as well in a bygone day, so perhaps the man just lies when he sees an opportunity to misdirect the fanbase and same himself the opportunity for a WHAM moment in the books.
EDIT: Another point to take... the gods' ignorance
assuring the gods' ignorance is probably the most Bakker plot device imaginable.
