My initial "take" on what was going on when reading the end of TUC is the stillborn was due to her having the Eye - but then it appears she still "has" it after the births, so I was simply confused about the relationship between the Judging Eye and dead fetus in the womb - either that's true and something more/else is providing Mimira with the Eye or it's wholesale incorrect. I find the No-God "causing" the death of one of the twins to be quite the cool speculation, but to me it's unclear the timing of events given how briefly the book treats this. Everything happened so quickly once Kel was in the carapace.
Again, before I read this thread ( or any of the forum until I finished TUC ), I "read"/thought that the Mutilated was in the head scratching phase of trying to figure out how to get the thing to work. I "felt" they were uncertain of Kellhus; hence, tried multiple times to kill him before he reached them ( competing probability trances, if you will - sorta like Herbert's treatment of the Guild's inability to see the future when in the presence of another clairvoyant ). Once he strode on in with little resistance from what was considered quite the powerful defense/creatures, their probability trance ( panic? ) let them to try to "turn" him, the cats with the chorae providing "incentive" for him to cooperate; but, maybe not since they didn't hesitate to kill him when they were freed up by Kel ( via "chasing" off Horned brother ) - bit hazy on this - not sure the arrival of the 4 Horn confused the "plan" and one spy reacted or if they were trying to kill him once they arrived. I think they quickly realized Kel could make the thing work when they heard him say the gods couldn't see him - marking him as no-god material.
I only bring these points up as they were my initial take on things - which is important not to lose our first impressions, they could be the most correct. While I love chewing the fat with you fine chaps, "studying" the work can lead us astray if we're not careful. We're discussing outside the initial read which is full of richness ( suspense/momentum/context - we're in the throws of the story ). I think Bakker intended some obfuscation here to add to the mania of what was happening. All in essentially a single, brief scene we have Kellhus goes salt, Serwa comes out nearly/completely ruined from a fight that appears accomplished nothing, twin births ( one dead ) ... and the small matter of the arrival of Mog. The speed of these final events denote confusion, by design I think.