So, I was trying to do a little research on the Inverse Fire, trying to discover if there is evidence that anyone had seen it and not been converted, when I stumbled upon an "answer" (or at least, something of a satisfactory explanation for myself) to something that has always bothered me: the Womb-Plague. I present what might be a new theory.
At first blush, it made no sense. What kind of garbage weapon makes your enemy immortal? Sure, it extinguished future generations of Nonmen, but if you could kill all the women, why not kill all the men too and be done with it? I tried to explain it to myself that perhaps the Tekne was incompletely known or was unable to be wielded effectively, but both of those came to me as hollow explanations.
A while back, I took to think of why they would want to keep them alive for so long. Was it just to torture them? That didn't make much sense though either, since they could have had more victims if they let them continue to procreate. Something was missing but I didn't have the time to find it.
In researching the Inverse Fire, I wanted to see who had seen (or most probably seen it) and what happened to them. I believe I might have found a much more convincing explaination of the Womb-Plague instead. Ready for it? It was not a weapon at all, it was an enlistment. Even more to the point, it was given to remake the Nonmen in the Inchoroi's image.
Follow me through here: as the Inchoroi wait in the Ark during the Second Watch, in the company of the traitor Nonman king Nin’janjin, I believe they realize two things. One, that the Inverse Fire can effect Nonmen (and men as well) and two, that the Nonmen are not all that unlike themselves. Realizing that it would be easier to fight their damnation collectively, the Inchoroi decide to set the Nonmen on the same path they took themselves, in the hopes that the Nonmen would turn willingly to the Inverse Fire and in the interest of their own salvation, help bring about the sealing of the world from the Outside.
The fact that all the women are killed in this plan is very salient here, since it cuts off any idea of "carrying on" through progeny. The eternal life granted leaves them to work as long as they need to avoid damnation, faced with no other real option for self-preservation.
Certainly seems logical, how much easier would it be to reduce the world to 144,000 souls if your forces working toward that end are about that number or more?
I don't know if this is "right" in the strict sense, but I know it makes a lot more sense to me this way then the idea that the Womb-Plague was a failed weapon. Failed enlistment tool, yes, definitely.
Hopefully this makes sense outside my head though...