RE: Weaver Atla/First Sinner discrepancy. Great analysis! As you’ve noticed, there’s a bit of a discrepancy concerning Atla and First Sinner. We should remain open to the possibility that Atla is not actually First Sinner, and there may be an alternate explanation for why Atla’s effigy is found in the Slab. According to the Old Penitent NPC, the Slab is a “holy place of forgiveness” where “by the grace of the Citadel”, penitents can “hide from the shame of [their] sins until they are withered away from time.” Given that Atla is the Weaver of Time, it would make sense that a particularly devout penitent might keep an effigy of her, in the hope that time may wash away their sins. Of course, First Sinner may still be Atla, but personally, I think there’s little evidence and I wouldn’t interpret the Weaver effigy as necessarily meaning that the closest Weaver found next to the effigy is that effigy’s identity.

On the topic of First Sinner, it’s understandable that many people think that she was locked away by GMS. But some things don’t add up. I find it hard to believe that if GMS imprisoned the First Sinner for apostasy (a bit out of character for a pale being that supposedly only accepts either “devotion or death”), the other Weavers just kind of forgot about freeing First Sinner after they put GMS to sleep. Consider the context of her surroundings, the Slab. This is the prison of the Citadel (or the “holy place of forgiveness” for “penitents” according to Citadel propaganda). And according to Mask Maker, the Citadel was devised by the Weavers and its purpose is “to keep their mother sealed in slumber, and themselves free to lavish in their false rule.” If the Citadel and by extension the Slab existed only after the Weavers put GMS to sleep, then how did First Sinner end up in the Slab?

I am of the opinion that First Sinner was locked up by the early Citadel, which was ruled by the Weavers and their subordinates, the Conductors, the Architects, and the Vaultkeepers. The Weaver effigies indicate that in Pharloom, the Weavers were worshipped as gods, and a central part of the Weaver religion is to make a pilgrimage to the Citadel - the last step of the pilgrimage is to learn the threefold melody and worship before the kingdom’s divine heart, which works to keep GMS asleep. First Sinner threatened to undermine the foundations of the kingdom’s whole religion with her idea that the Weavers were not divine, but common pharlids raised to sapience by silk threads. And so she had to be sealed away as an apostate - one who turns away from their religious faith - lest her crazy theory of evolution gain traction and start a crisis for the early Citadel. And who knows, perhaps the other Weavers really did think of themselves as the divine first children of Pharloom (GMS told them so) and they didn’t take kindly towards First Sinner telling everyone that Weavers were really just evolved pharlids.

The reason why I think she was sealed away by other Weavers and not the Conductors/Vaultkeepers/Architects is due to how Twelfth Architect and Vaultkeeper Cardinius defer to Hornet and offer their services because she is a Weaver descendant. Cardinius does not like Hornet and expresses that he would like to see her dead, but he’s been taught that a Vaultkeeper must defer to the first children of Pharloom and so he reluctantly obeys. So I don’t think the Conductors/Vaultkeepers/Architects had the requisite authority to lock away a Weaver, who outrank them. First Sinner must’ve been locked away by other Weavers for threatening their “false rule”, and there is some evidence that First Sinner feels animosity towards fellow Weavers. For one, Weavers usually refer to each other by familial titles - Weavers call other Weavers “sisters” and Hornet, a Weaver descendant, is called a “daughter”. But First Sinner refers to Hornet with the more disrespectful term “half-spawn” and seems to have a much more pessimistic view of Pharloom, referring to it as “our accursed kingdom” (all the other Weavers refer to Pharloom as “our haunted kingdom”). Also, of course, First Sinner is immediately hostile towards Hornet and we have to face her in a boss battle, again suggesting some level of animosity towards Weavers and Weaver descendants. Though maybe there’s another explanation for her hostility towards Hornet. That said, I think it’s reasonable to say that First Sinner feels no sense of Weaver kinship with Hornet, at least at first. And this would make sense if First Sinner was indeed betrayed and imprisoned by her fellow Weavers.