Zodiark's Codex entry what do we think about it?

[Cleretic]

It's partly a thing we can blame on the writers – they chose to write the souls within Zodiark as still individual and lucid all this time, when they could have been long dead with their souls returned to the sea and only their remnant corporeal aether powering the primal. That was the tragic situation we generally took to be the case in Shadowbringers and it amplified the tragedy of what was driving Emet. Somehow having it be an actual arranged possibility for them to be revived later weakens that whole earlier plotline.

I honestly never read it as 'the souls fell out and are in the aetherial sea'; the third sacrifice was a confirmed element as far back as 5.0, and that particular part only really makes sense if there are souls still in there. After all, we heard the tale from Emet (and Fake Hythlodaeus, who's basically an extension of such for these purposes); he knows and accepts how the life cycle works, so he wouldn't be so torn up over this unless it wasn't working as he expects it to. So yeah, them still being in there, and the Ascians being the only ones with a plan to get them out of there, seems to be how the story was always intended to work, it was just made explicit rather than remaining clearly implied. I've always had the question of if Zodiark was powered by souls or merely aether, but that's really just a semantic difference given that they were sacrificing lives to it anyway; the answer doesn't matter and would change nothing.

I think the core thing we learned about those guys in Endwalker wasn't actually related to the situation going on around them--none of that really seemed to change, although the context was colored in more--and more about what it's like in there. The fact that they seemed to be conscious up until the point of the sundering, and then 'drifted into a waking dream' until the events around when we turned up. Their general mental state, too, was news: that only one actually seems to regret their sacrifice, and the rest are more mourning--depending on the individual--either the fact it had to happen, or the fact that it doesn't seem to be working. (Or are Hythlodaeus, who seems kinda just okay with it.) In fiction, one person's story trumps a swathe of just plain facts, so I will note that that one guy was probably representative of a larger group of regretful people in there, but he was a minority even among the people we did hear from. Most of them seemed content with their sacrifice, they just wish it worked.

EDIT: All of this is to say, yeah, the writers wrote this, but they wrote this with intention and reason; it accentuates the tragedy of both the sacrifices and the Ascians, as well as an irony that the third sacrifice was all for the purposes of returning people who, for the most part, didn't want their sacrifice undone.

[Alleluia]

I honestly never read it as 'the souls fell out and are in the aetherial sea'; the third sacrifice was a confirmed element as far back as 5.0, and that particular part only really makes sense if there are souls still in there.

I felt the exact opposite. They sacrificed themselves to power a primal. Sacrificing yourselves isn't really sacrificing yourselves if you are still there. Thus the third sacrifice was an attempt to bring back the dead by using Zodiark's power to reconstruct/rez them from nonexistence. Which never works well (look at Eda. Or Bahamut). I thought they were enacting that plan as a result of tempering and were ultimately just unknowingly serving Zodiark more aether in an endless cycle. Cus they were tempered and that's generally what a primal's tempered do. As of 5.5, we had zero reason to believe a "resurrect the dead" plan would actually work, especially when those dead had been blendered into pure aether to power up a primal enough to stabilize a planet.

Then 6.0 happened and the potential effects of tempering on the convocation was kinda thrown out the airlock, and the moon was haunted, and my understanding stated above wasn't an option anymore.

[Iscah]

I felt the exact opposite. They sacrificed themselves to power a primal. Sacrificing yourselves isn't really sacrificing yourselves if you are still there. Thus the third sacrifice was an attempt to bring back the dead by using Zodiark's power to reconstruct/rez them from nonexistence. Which never works well (look at Eda. Or Bahamut). I thought they were enacting that plan as a result of tempering and were ultimately just unknowingly serving Zodiark more aether in an endless cycle. Cus they were tempered and that's generally what a primal's tempered do. As of 5.5, we had zero reason to believe a "resurrect the dead" plan would actually work, especially when those dead had been blendered into pure aether to power up a primal enough to stabilize a planet.

This. As far as we knew, their souls were either long gone back to the aetherial sea or destroyed to fuel the summoning. That's why the worldwide sacrifice was such a grave and noble undertaking, not just a temporary "stand here for a while and hold the aetherial fort until we can let you out again". Include that escape clause as in inherent part of the plan and it stops being a sacrifice and turns into just being a duty.

The apparent tragedy of Emet-Selch and presumably all the Ascians as of 5.X, was that they were fixated on this plan that if they just gathered enough aether they could undo the sacrifice and restore their brethren, when really it was a false hope all along.