I kinda assumed the hardware or the knowhow was lost in the crash.
I suspect the Nuke was a one off functional device, saved for a real emergency?

They clearly had to have more than one, and to have used them in the antique wars. Even with his ubermensch deductive reasoning, Kellhus' knowledge of the effects of the weapon, had to come from somewhere. Especially detailed knowledge of things like radiation sickness among the survivors, implies that much at least. Predicting the effects of a technology that otherwise doesn't exist in the world really stretches suspension of disbelief, even for Kell. He has to know what came before to know what comes after.

Almost their entire population died in the crash, including most of their experts, and most of their technology was also smashed.  They've been forced to use whatever they could jury rig into functioning and salvage.  They've been using half trained, trial and error bioengineering using what remaining semi functional tech they have, because that's all they got.  When they fought the Nonmen they used up almost all their remaining weaponizable technology and that's what ultimately lead to their defeat because their Weapon Races alone weren't strong enough to prevail.  It's surprising that they had a nuke left, but the Consult has had two thousand years to search the Ark and try to repair anything they found.

Fascinating. This makes a great deal of sense. Thanks! I need to alter a few assumptions; I had the impression it was more a predisposition of their species to utilize the biologic components of the Tekne over the technological, and any loss of ability to comprehend it was due to a cognitive decline from their repeated augmentations.

Golgotterath itself seems to be the source of the Tekne, and skin-spies among other things seem to be a new invention which implies it's still functional post-Arkfall to some degree, so the infrastructure, as it were, already seems to be there. Perhaps this means it produces biological Tekne only? I've always thought if it could make one, it could make the other. But I suppose there are different classes of 'Tekne', or perhaps this has simply become a blanket term for any artifacts the Inchoroi brought with them, regardless of origin? It does explain a finite supply of some Tekne, but not others.

Please correct me if I'm wrong, but isn't Ishteribinth the single surviving Mansion anyway? So king of one would likely be king of the other, no?

I found Cleric's explanation satisfactory, that the Nil-Giccas persona is dead. Also possible is that Nin-Ciljiras' tenure could be a sort of regency. We don't yet know how the Intact view their Erratic brethren, but even if they do continue to revere him and consider him "alive," it seems unlikely they would accept the rule of an Erratic (who is more likely to be interested only in their destruction, for memory's sake, rather than their management).

Something else:

Genealogy of the Gods; Yatwer and Gilgaol are mentioned as Sister and Brother. As all the Gods are all Gods and so sibling to each other or as Yatwer and Gilgaol are specifically Sister and Brother? If so, who "fathered or mothered them (whatever else)" and so on?

My personal interpretation is tied to the perception that the Outside ("inside", per Kellhus), and all the beings that dwell within, are a reflection of living consciousness in Earwa. The God of Gods would be the collective reflection/manifestation of all souls. Each individual God would perhaps be the manifestation of a particularly common sort of Jungian archetype among human cultures, given enough strength to become a sort of life after reaching a certain threshold of commonality. As society evolves into more complex forms, new ideas take precedence and new gods are "born". Among primitive tribal cultures, fertility and war were among the first such themes recognized and soon worshipped, making them among the Eldest, with the more familial relationship described in religious circles as a recognition of the overlap in their respective desmesnes, as previously mentioned.

Though I suspect that any particular deity's relative power doesn't necessarily require direct worship, only a prevalence of their sphere of influence among mass consciousness. Yatwer has been the chosen deity of the oppressed, not just fertility, and in recent years with Kel's rather violent despotism, there's a whole lot of folks around feeling oppressed, giving her by far the most power in the Outside, currently, and thus her prominence in the novels.

Or so goes my theory. Thoughts?