An ominous premonition? (Slight spoiler for the Studium quests)

[RyuDragnier]

When Emet showed us the Source and its reflections in the Ocular during Shadowbringers, he had them topologically arranged in a circle rather than a line (i.e. the First and the Thirteenth are both immediately adjacent to us). If the lifestream links the shards to each other, then perhaps the Ourbouros isn't just a symbol of rebirth, but also represents the flow of souls from one shard to the next. That being said, if you had a calamity causing a large loss of life and resulting displacement of souls, you would then expect the rejoining to cause two adjacent shards to collide rather than the shard in question and the source. You'd also need eight wedges between seven shards if you were partitioning the lifestream.

Unless there's a natural predisposition for the aether to return to the Source, which is something that makes sense with the knowledge that the Calamities only effect the Source after a Shard's destruction, and no other Shard. Which means the Source itself attempts to pull the Shards to it, but Hydaelyn or Zodiark's power (maybe both) kept them from coming any closer, until the balance is out of whack, at which point a Shard gets so close that it gets absorbed back into the Source.

This process results in the aether going haywire, causing massive ecosystem changes to the Source itself...as seen by how Coerthas, which originally had some greenery to it before Bahamut, is now a bit of a frozen wastes (in comparison to the Dravanian Forelands and Hinterlands which show how it probably should look more like). Without Hydaelyn and Zodiark's power here, it's very likely the Shards are getting pulled slowly closer to the Source, which will result in the one Calamity to end them all. The Seven Wedges are likely going to be putting some force there to stabilize each Shard's connection to the Source so there's nothing pulling them together.

[Lyth]

The thing that I'd like to know is how the shards are connected to each other, and in what direction the lifestream flows.

If someone dies on the First, for example, where does that soul go? Does it stay in the First, does it travel to another shard, or does it travel to the Source? If it can travel to the Source, can the reverse also be true, or is the flow unidirectional?

If every shard connects back to the Source directly and the direction of flow is unidirectional, then over time, every Soul would eventually end up back on the Source, and individual shards would depopulate over time even without forcing a Rejoining.

The more general form of this question is how the shards maintain a dynamic equilibrium with each other, such that the net amount of souls on each shard remains relatively constant over time. Even if the flow is bidirectional, if every shard was only connected to the source, the source would need to have on average around 6x the birth and death rate of the other shards to maintain balance (13x originally). If the Source is only directly connected to the First and Thirteenth and every shard is connected to two others, then they all can have roughly identical birth and death rates.

[KageTokage]

It seems implied that every shard has its own distinct Lifestream as Hydaelyn had to specifically "ferry" the souls of Minfilia and Emet-Selch back to the Source from the First.

Though that in itself would further imply she has some level of control over the aetherial sea, which again raises questions of what the heck is going to happen now if she's somehow been exerting her influence over it since the Sundering, but is no longer present to do so.

[Cleretic]

Though that in itself would further imply she has some level of control over the aetherial sea, which again raises questions of what the heck is going to happen now if she's somehow been exerting her influence over it since the Sundering, but is no longer present to do so.

Good thing we found a couple gods of the afterlife wandering around, then, or that would be a WAY bigger problem.

[KageTokage]

Given that what we know of the actual "afterlife" vs. its portrayal in the various faiths, I can't help but wonder what Nald'thal's real purpose for being is.

[sidurgu-12]

Given that what we know of the actual "afterlife" vs. its portrayal in the various faiths, I can't help but wonder what Nald'thal's real purpose for being is.

with the introduction of dynamis its possible both the lifestream and 7 heavens/hells exist simultaneously.

[Lyth]

I would have thought that if the Lifestream of each shard was isolated from the others, that would be a bit like Ourbouros with the wedges driven into its back. If they flow into each other, that's where issues potentially can arise, if they're not in equilibrium.

The Amaurotians had a cabinet position dedicated exclusively to dealings with the Underworld/Lifestream (i.e. Emet-Selch). You still someone capable of addressing issues arising from it, ideally one who is good at identifying or weighing souls.

[Tehmon]

Speaking of the lifestream, do we know the state of the ancient souls sacrificed to Zodiark? How sundered or unsundered are they?
Either way, there is at least two fully unsundered souls ready to be rebirthed (in 100 years or so I presume but nevertheless), and, well, I feel like that needs to be addressed eventually?

[Lyth]

I'm not sure if it really matters all that much. There's a lot of variation amongst soul densities as it is, and that's even assuming that the Ancients themselves all had souls with identical density. I don't think that Hyth is at 'full' density given that Zodiark was sundered and only partially rejoined, and he was less magically adept than Emet to begin with. If Emet's soul gets recycled at a later point, the person who inherits it might end up being really good at magic with a longer than normal LB cast time.

[KageTokage]

I can't help but wonder what the "new flesh" in the prophecy could be referring to.

It could be figurative, but I could honestly see it being more literal in the sense of Etheriys creating some manner of lifeform(s) to try to address the instability caused by the Sundering coupled with the absence of the two gods. If souls are born from the star itself, it could stand to reason that at one point it also bestowed flesh upon them, perhaps with the Ancients being the original lifeforms and their unique Echo-blessed souls a testament to that.