Tales From the Shadows Updated (SPOILERS ABOUND)

[Grimr]

it would seem everyone needs a refresher on why they did time travel in the first place. Eight umbral calmaity hits black rose is used Garlemald magiteck is non functional and other city states are void of aether think the empty but on a larger no honestly think Novrant and the first cause its basically that but eorzea. Emet-set and elibus ( unless they were killed though out the timelines)still exist in that doomed era. I don't even know if middy can reverse that emptiness, not even cid could.

What the exarch said was true the tower needs to go back to eorzea to ensure the 8th calamity of that nature doesn't happen. Until it leaves the first, there will be a calamity of epic proportion that will necessitate the use of the tower again. Maybe when we defeat zenos the tower will vanish. But until it has nothing will have changed.

I will not discuss the 3 timelines of zelda here. My attempted knowledge comes from Chrono Trigger and loz MM ( song of time anyone)

It is simple cause and effect.

[Iscah]

it would seem everyone needs a refresher on why they did time travel in the first place.

I haven't seen anyone here indicate that they do not understand those facts.

Also the Eighth Umbral Era city-states world (and the Empty) are not "void of aether". That description goes to the opposite state, as seen in the World of Darkness.

An umbral (Light) charge brings the flow of aether to a halt. It isn't destroyed, just frozen and inhospitable to life. If you think of aether as water then the Eighth Umbral Era is an ice age.

Up until now we had to assume this was an irreversible effect, to justify the writers' logic that it made sense for them to throw all their ingenuity into saving another version of the timeline over improving their own. The ending of this new story seems to imply otherwise. Perhaps it's not looking as bleak as it once was and the aether is slowly recovering, even though earlier generations thought it couldn't.

What the exarch said was true the tower needs to go back to eorzea to ensure the 8th calamity of that nature doesn't happen. Until it leaves the first, there will be a calamity of epic proportion that will necessitate the use of the tower again. Maybe when we defeat zenos the tower will vanish. But until it has nothing will have changed.

It is simple cause and effect.

You're confusing the cause and the effect.

What the Exarch said is that if the Calamity is averted and the original "dark future" timeline ceases to exist, that may cause the Crystal Tower to vanish along with the entire timeline it came from. There is no "going back to Eorzea". There is no Eighth Umbral Era and no original location in Eorzea for it to go back to. It simply ceases to be.

What you seem to be getting from this information is that the tower must return to where it came from to prevent the Calamity. This is not the case. Even if the Exarch's prediction was correct, the tower's absence would simply be an indicator that the timeline had changed, not the cause of it changing.

Additionally, you're playing with paradoxes if you assume that the necessary outcome is that the original timeline will be overwritten and the tower will vanish. The consequences of that approach form an unresolvable loop:

1. G'raha travelled back in time and to the First to prevent the Calamity.
2. The Calamity is prevented and the timeline overwritten.
3. Because there was no Calamity, G'raha did not travel to the First.
4. Because G'raha did not travel to the First, the Crystal Tower was never moved to the First.
5. Because G'raha and Tower were never in the First, nobody was there to kill the Lightwardens and remove the excess Light.
6. Because nobody removed the excess Light, the First is still full of Light and primed for rejoining.
8. Because the First is still full of Light, Black Rose happens.
9. Because Black Rose happens, eventually G'raha travels back in time to prevent...

If this is the scenario you want to play, where do you stop that paradox loop? Even if it somehow didn't lead to the First being re-doomed, I would find it overly convenient if the tower vanished and nothing else. What happens to the Crystarium? What happens to any technology or building materials they ever derived from the artifacts in the tower? The whole town could literally fall apart - assuming it ever existed. Do people remember he was there, or are the memories erased as well?

The scenario in which the tower vanishes is fraught with paradox and the risk of undoing the very thing it was meant to achieve. Other scenarios allow for time to be altered without this happening. We seem to be in one.

The simpler conclusion is that G'raha's expectation was incorrect. From all the evidence we now have, the specific calamity he came back to prevent can no longer occur. The First's Light has been dispelled and is no longer available to supercharge a Black Rose explosion even if it was set off. Even if a different disaster happens, it will not match the scenario that G'raha learned of as history in the dark future, and events cannot lead to that particular future any more.

The non-collapsing split timeline makes the most sense because it means that G'raha's knowledge of the dark future doesn't form a paradox once that future is "averted". It still exists. He was there, even though he can't return.

My attempted knowledge comes from Chrono Trigger and loz MM ( song of time anyone)

I don't know about Chrono Trigger, but the time travel logic of Majora's Mask is not applicable here.

The Song of Time rewinds time so he can live those three days over and over again, with the things that happened one time not carrying over to the next. Everything resets every time you go back. (Alternately, every time you go back, you're leaving that timeline to its doom and creating yet another one that will probably share the same fate.)

Time travel here is the opposite. Outside of the exceptional circumstances that cause the split in Shadowbringers, there is a single constant timeline and (as seen in Alexander) your time-travelling activities can merge into the sequence of events that were always there. If you go back to a time and place that you previously visited, you will encounter your past self there. You can't simply attempt the same day over and over - either you'll get a pile-up of alternate selves or you're definitely splitting the timeline with each attempt.

Additionally, Link is not coming from the future to change the past, but is simply manipulating the present. Meanwhile Ocarina of Time does involve changing elements of the past to affect the future, but it runs on a completely different style of time logic to what is happening here. The mechanisms are simply not compatible.

The price and frequency of time travel is also very different. Link can move freely through time as often as he likes with no ill-effect, and must do so to drive the plot. G'raha travelled once, at heavy personal cost (again, I think the majority of his crystallisation happened as a direct consequence of the trip) and will not do so again. Once he arrives in the First, the actual time travel element of the plot is over and everything else happens in real time.

[Grimr]

Snip

Let's start shall we
1.
A few posts earlier people were asking why didn't cid just work on getting aether going again. There was no request for it but i thought it would be helpful to bring it up.

2.
It is called the empty for a reason no need to be technical about it. The aether is stale non moving and nothing grows in the empty and absorbing too much aether turns whomever into a stale non aether moving zombie so to speak.

3.
Early on the exarch forbade anyone spending the night in the tower because it could vanish. Now elibus and emet were defeated and the exarch was turned into a crystal but the scion did not go back to eorzea nor did the tower and why is that?? The only logically conclusion one can derive is the future has not changed and i am certain all will be made aware of it in probably 5.4 or 5.5 not entirely sure. I suppose there could be multiple timelines but I'd rather not think about the 8th umbral era timeline cause it is depressing even with middy awakening . There is no going back to 7th astral era state in that timeline.

4.

I suppose chrono trigger is more applicable here than majoras mask but ( and regardless i have played more than enough time travel games to list here) more or less it is cause and effect action and reaction example.. Killing the queen's floating city in chrono trigger what else in the present eliminates it from the future when lavos emerges. Now technically we on the source would not notice it but on the first the tower would disappear and so would the modifications and on that action alone would the future be changed to a point the tower was no longer needed to avoid the 8th umbral calamity.

5
I give the the zenos factor. It is said that zenos destroyed all of black rose because he does not want anything to get in the way of his hunt( also probably why he killed varis). The thing is it safe to assume that he would have also destroyed black rose in the future timeline as well which kinda leaves me to believe black rose may not be responsible for the 8th umbral calamity either so either the exarch lied or se created a plothole.

[Alleluia]

3.
Early on the exarch forbade anyone spending the night in the tower because it could vanish. Now elibus and emet were defeated and the exarch was turned into a crystal but the scion did not go back to eorzea nor did the tower and why is that?? The only logically conclusion one can derive is the future has not changed and i am certain all will be made aware of it in probably 5.4 or 5.5 not entirely sure. I suppose there could be multiple timelines but I'd rather not think about the 8th umbral era timeline cause it is depressing even with middy awakening . There is no going back to 7th astral era state in that timeline.

The logical conclusion is that the future that led to that tower ending up in Norvrandt didn't change, yes. And that's right, it didn't. It still exists. But we're not on that pathway anymore. Our future has diverted to another path.

An example:
You're floating down a river. You turn around and throw a shrapnel bomb really far behind you. It explodes and creates a new channel in the river, the bomb's fragments floating down this new channel you made. The bomb is still from your boat and you still threw it, so the shrapnel bomb does not disappear. But what's left of it is now physically present and persistent in the new channel of water that was created. Water continues to flow down both river channels.

The Tower is the bomb.


As for the 8th umbral timeline being depressing... I mean, yes. However, I think they have some hope. I mean, yeah you have Midgardsomr, but also, Black Rose likely didn't effect the world beyond the three great continents. Calamities are always localized and strongest in Eorzea (prolly b/c the veil btwn worlds is thinnest there or something). Its why the water calamity didn't drown the world, for example. So, Black Rose was really bad and we know it was released in Ala Mhigo, effecting both Aldenard and Othard. We can assume it probably effected parts of Ilsabrd, too, since that connects Othard with Aldenard. Probably also effected the surrounding seas cus there's aether in the water, too.

But its effects had to dilute at some point, or else there'd have been no living on the continents at all for the prior 200 years. And I doubt it crossed the oceans and hit either the new world or the southern continent very hard, if at all. So, there's hope that they can live in those new lands, or possibly figure out a way to start seeding the aether back in from the fringes and rebuild.

[Iscah]

If we're to assume that moving Syrcus Tower from the Eighth Era to our version of the First is what forked the timeline...

I don't see any reason to assume that's what caused the timelines to diverge - otherwise our time travels in Alexander split the timeline twice, and that couldn't have happened because both time-travel instances rely on time acting as a loop. Particularly the second time during A12 where we save our past self - there simply cannot be a version of events where we fail to do so, because that would be a paradox.

It seems logical to me that the point where the timelines diverge is the point where the original future is no longer possible because new events are incompatible with what G'raha knows to be true. Specifically, preventing the calamity that is a key event in creating the world as it exists in that timeline.

It can be hard to explain but a change in known circumstances is not the same thing as a change. The "three years ago" incident in Alexander is the easiest example - the timewarp and the "interfering" goblins were always part of the single version of events that played out there, but Mide doesn't know about them until she witnesses it a second time from a different perspective.

By the same logic, when the Crystal Tower first appears in Lakeland, that wouldn't be a change to some previous "untouched" version of events, but part of the single version of that world's history.

Whatever exactly triggers the split, my personal line of thinking is to place it as late as possible in the chain of events. That well could be the first time the Exarch makes contact and Thancred is taken - though (dependent on some specific hypotheticals) suppose the record of this event doesn't survive through to the far future to be relayed to G'raha. Suppose all the Scions are "taken" but the records that survive the calamity are unclear about this, and they are misunderstood to be victims of Black Rose. This would mean that even after the Exarch starts affecting events in the Source, the timelines have not yet diverged until we do something that more conclusively changes things.

Perhaps it's whether or not the Exarch successfully "interferes" with our fight with Zenos. Perhaps it's whether we choose to listen to him or not. Perhaps it doesn't even diverge until we succeed or fail in defeating Hades? But again this is very speculative.

In the original timeline since we never get body snatched we kill Zenos's body at Ghimlyt Dark when we fight Elidibus within it, rather than passing out and getting saved by Estinien.

I have speculated on this idea before - specifically that our defeat of (what the Garlean army believes to be) Zenos is the tipping point that eventually drives them to employ Black Rose. However, we have no reason to consider it a fact, unless perhaps we're intended to interpret the trailer as an alternate "how it went in the other timeline" version.

3. Early on the exarch forbade anyone spending the night in the tower because it could vanish. Now elibus and emet were defeated and the exarch was turned into a crystal but the scion did not go back to eorzea nor did the tower and why is that?? The only logically conclusion one can derive is the future has not changed and i am certain all will be made aware of it in probably 5.4 or 5.5 not entirely sure. I suppose there could be multiple timelines but I'd rather not think about the 8th umbral era timeline cause it is depressing even with middy awakening . There is no going back to 7th astral era state in that timeline.

Suppose (for some arbitrary reason) I decide to throw a ball at a window.

"The glass might break," I say. "You should stand back so you don't get hit by it."

I throw the ball. It bounces harmlessly off the window.

Your argument regarding the tower is equivalent to insisting that because the glass is not broken, I must not have thrown the ball yet.

The Exarch planned to change the course of time. He warned people to stay away from the thing that might change in a harmful way as a consequence of his plan. His prediction of that consequence turned out to be inaccurate.

Time has been changed, and there was no great fanfare to announce that it had happened. But you can observe that the situation has changed in other ways, and those changes mean that the events G'raha knows as "the history of how the Eighth Calamity occurred" cannot come to pass. The Light is gone from the First and cannot supercharge Black Rose in the diminished chance that it is still used in the Source. Therefore, unless those specific circumstances return, we cannot still be on the same timeline that leads to the original future he came from.


As for "no going back to the Seventh Astral Era" for the other timeline? No it won't, because time moves forward. They can't return to the Seventh Astral Era but they can work towards an Eighth.

4. I suppose chrono trigger is more applicable here than majoras mask but ( and regardless i have played more than enough time travel games to list here) more or less it is cause and effect action and reaction example.. Killing the queen's floating city in chrono trigger what else in the present eliminates it from the future when lavos emerges. Now technically we on the source would not notice it but on the first the tower would disappear and so would the modifications and on that action alone would the future be changed to a point the tower was no longer needed to avoid the 8th umbral calamity.

This is not the cause and effect you are looking for.

Making the tower vanish will not avoid the calamity.

The tower might have vanished as a side effect of the other actions we undertook to prevent the calamity. It did not. It does not have to.

To return to my analogy: throwing the ball = acting to change time; breaking the window = making the tower vanish.

The breaking glass does not cause the ball to be thrown.

5. I give the the zenos factor. It is said that zenos destroyed all of black rose because he does not want anything to get in the way of his hunt( also probably why he killed varis). The thing is it safe to assume that he would have also destroyed black rose in the future timeline as well which kinda leaves me to believe black rose may not be responsible for the 8th umbral calamity either so either the exarch lied or se created a plothole.

As others have already covered at this point, there are variables. We don't know the timing of when Black Rose would have been used - perhaps it was before Zenos made his move to assassinate Varis. Perhaps he missed that one bomb that they ultimately set off.

We know that Emet-Selch was scheming to make use of Black Rose to trigger the calamity. We know it has aether-halting properties. And we have no reason to doubt G'raha's recounting of the history of his timeline - or Omega's more immediate records in A World Forsaken.

It's less of a narrative stretch to assume Zenos didn't stop it in the other timeline than to assume that the calamity (the exact one as known to G'raha) is still on track to happen despite all evidence indicating that it has been averted.

[Rosenstrauch]

It seems logical to me that the point where the timelines diverge is the point where the original future is no longer possible because new events are incompatible with what G'raha knows to be true.

It can be hard to explain but a change in known circumstances is not the same thing as a change. The "three years ago" incident in Alexander is the easiest example - the timewarp and the "interfering" goblins were always part of the single version of events that played out there, but Mide doesn't know about them until she witnesses it a second time from a different perspective.

By the same logic, when the Crystal Tower first appears in Lakeland, that wouldn't be a change to some previous "untouched" version of events, but part of the single version of that world's history.

I think the problem I have with this assumption is that it presumes that, in both timelines, Syrcus Tower suddenly appeared in Lakeland, being ridden by the time traveling G'raha Tia. This can only work if G'raha Tia traveling back in time is the result of a causal loop.

To elaborate: Causality is a series of causes and effects. When a cloud rains, the street below gets wet. And each cause is itself the effect of a previous cause. When water evaporates, it rises to form clouds, which will then rain at a later point. This chain of events, when examined from end to beginning, will always have a point of origin. A man slipped on the wet street. Why? Because it rained that day. Why did it rain? Because clouds had gathered in the sky. And so on, leading all the way back to the birth of the universe—assuming nothing existed before then. Finally, if any two points on this chain of events are taken and examined, it can be reasonably stated that the earlier of the two caused the ensuing events that led to the later of the two. Water evaporated, leading to a man slipping on a wet street.

This probably sounds really patronizing, and I'm sorry for that, but I need to establish this because it is the entire basis of my line of thinking when it comes to time travel, time loops, and split timelines.

Time loops, otherwise known as causal loops, are a nightmare to map in terms of cause and effect. This is because unlike regular causality, there is no discernible point of origin for the chain to begin at. Mide's beloved and his followers attempted to summon Alexander. Why? Due to a series of events "starting" with Mide and her beloved appearing in the distant past. Why did that happen? Because Alexander sent them back in time. Why did he do that? Because of a series of events originating from Mide's beloved and his followers attempting to summon Alexander. And so on. This is what's known as a "Bootstrap Paradox".

To show how this conflicts with the split timeline in Shadowbringers, consider the following: If G'raha traveling back in time was already part of Timeline A (the Eighth Era timeline), then we would have to stop and ask what meaningful effect him traveling back in time had on Timeline B (the one we witness). We know he's not in a causal loop, because the end result of his time travel was the apparent creation of a future where the Eighth Umbral Calamity as it was known in Timeline A never comes to pass. For example: Let's say in the original timeline he never founded the Crystarium. This in turn led to him not having the resources needed to make his summoning spell a reality, and thus he never called over any of the Scions or the WoL. What, then, happened to make him want to found the Crystarium in Timeline B (the Bright Future timeline) that didn't happen in Timeline A? Without an outside event to influence his choice, there can be only one outcome to the decision on whether or not to found the Crystarium, and we know for a fact that he did in the one timeline we can observe.

And the above holds true for any event in the sequence. Without an outside event to knock the chain of events in a different direction, there is no reason for anything to play out differently in Timeline B than in Timeline A. And we don't know of any outside events other than G'raha traveling back in time, so it stands to reason that, in the absence of evidence to suggest otherwise, the most sensible point of divergence is G'raha traveling back in time. An admittedly weak conclusion: We don't know that Syrcus Tower arriving on the First wasn't part of the Eighth Era timeline to begin with. We also don't know that it was. And unless a new lore book comes out to explain this, we will never know for sure. But I'd rather something we do know (G'raha traveling back in time) be the cause of the divergence than something we don't (??? happens irrespective of G'raha traveling back in time).

... as an aside, I think I'd be pretty livid if, in 5.5, Fandaniel proceeded to pull Black Rose out of nowhere and dump it on us. And it turned out Emet-Selch was just hamming it up, and we were never even close to pulling the First back from the brink in time. And then someone pulled a Louisoix and sent us and the Scions 2XX years into the future, which is why everyone thought we died when Black Rose was deployed. And then G'raha resealed himself in Syrcus Tower and developed amnesia so that he doesn't know how all this played out, which is convenient because nobody alive in the Eighth Era knows either, and their version of events is just inaccurate hearsay. I wonder if such a turn of events would satisfy those who say the story has to resolve in a time loop—that's what I think would have to happen in order to enable it, at any rate.

... as another aside, I think my post drifted away from my original line, and I failed to demonstrate how G'raha traveling back in time would have to be a causal loop if G'raha traveling back in time was something that happened in both timelines. Or maybe I did, and I don't realize how. I blame myself either way, and can't muster up the energy to care enough to try again.

[Iscah]

I think the problem I have with this assumption is that it presumes that, in both timelines, Syrcus Tower suddenly appeared in Lakeland, being ridden by the time traveling G'raha Tia. This can only work if G'raha Tia traveling back in time is the result of a causal loop.

This would probably be easier to explain with the diagrams I eternally say I'm working on... but anyway.

Firstly, G'raha does not travel back in time "in both timelines", even if you suppose his arrival in Lakeland immediately causes the split. There is only one instance of him time-travelling, and he travels from the dark future to a point before the two timelines diverge.

Secondly - here's where time gets twisty - as much as we say "he came from the bad timeline and changed things so he ended up in the good timeline", that's a simplification from our viewpoint because the story takes place in the good timeline.

Because the diverging timelines would each have a copy of everything that exists at the moment where they split apart, then (at least on the assumption that the split happens sometime between 4.4 and 5.0) that "everything" includes the Exarch as a separate entity to young G'raha Tia.

This is hypothetical and unobservable, but logical. In the bad timeline, the Exarch would still already be long established as the leader of the Crystarium. He would still be desperately trying to reach us - and he would fail. Ultimately all he can do is watch helplessly as events come to pass in accordance with the history he learned in the far future, and wait for the moment where the First is rejoined and everything dissolves into aether - himself included.

(But if he somehow survived and continued to observe events for another two hundred years, he would ultimately see his younger self depart to the First to repeat the cycle.)

It's in this version of events that we find the causal loop. The events of the bad timeline cause G'raha to travel back in time; G'raha's actions do not successfully alter the timeline; the First is rejoined and everything happens in the way that leads back to the future he originally came from.

The split in the timeline breaks us out of that loop (or rather, changing events breaks the loop and forces the timeline to split) and creates a second path that does not need to lead back to the dark future, because that future continues to exist independently and provide the origin point for both the good-timeline and bad-timeline versions of the Exarch.

To show how this conflicts with the split timeline in Shadowbringers, consider the following: If G'raha traveling back in time was already part of Timeline A (the Eighth Era timeline), then we would have to stop and ask what meaningful effect him traveling back in time had on Timeline B (the one we witness). We know he's not in a causal loop, because the end result of his time travel was the apparent creation of a future where the Eighth Umbral Calamity as it was known in Timeline A never comes to pass.

For example: Let's say in the original timeline he never founded the Crystarium. This in turn led to him not having the resources needed to make his summoning spell a reality, and thus he never called over any of the Scions or the WoL. What, then, happened to make him want to found the Crystarium in Timeline B (the Bright Future timeline) that didn't happen in Timeline A? Without an outside event to influence his choice, there can be only one outcome to the decision on whether or not to found the Crystarium, and we know for a fact that he did in the one timeline we can observe.

This example doesn't make sense because it picks a point where there's no reason for things to differ. There's no reason for G'raha to partly follow the same path of actions then arbitrarily stop and do something else. Even if the timelines had split at that point (which I don't believe they had), both versions of G'raha would carry the same intention to work towards saving the WoL. Both versions of events well might play out exactly the same across the two timelines until you reach the variable factor which is either G'raha's success at calling us, or our decision to respond.

This is exactly why I don't like the "time travel itself splits the timeline" idea (even without the events of Alexander seeming to disprove it). For as long as events remain consistent with the version of history that G'raha is working to prevent, it's much simpler to assume there is only one timeline than two running in parallel. They only need to break apart when the current situation is no longer compatible with that previous version of history.

I think it relies specifically on G'raha's actions since he's the only person with pre-knowledge of what will happen (or did happen from a future perspective) and what needs to be changed. Everyone else just acts based on the present situation. G'raha is a variable not because he "wasn't there before" but because he alone knows what's coming.

[Rosenstrauch]

Firstly, G'raha does not travel back in time "in both timelines", even if you suppose his arrival in Lakeland immediately causes the split.

That's not what I said. What I said is that you're presuming there are two timelines in which G'raha arrived with Syrcus Tower on the First. I am saying there is only one such timeline, and the second timeline has no interference from G'raha at all.

Because the diverging timelines would each have a copy of everything that exists at the moment where they split apart, then (at least on the assumption that the split happens sometime between 4.4 and 5.0) that "everything" includes the Exarch as a separate entity to young G'raha Tia.

I don't believe the split happened sometime between 4.4 and 5.0. I believe the split happened sometime after 3.4, but before an indeterminate period during the events of Stormblood. From the perspective of someone on the First, this specific point in time would be n years after Minfilia halted the Flood of Light, or 100-n years before the WoL's arrival on the First. This specific point in time would be, as I've said, the moment Syrcus Tower arrived on the First.

This is hypothetical and unobservable, but logical. In the bad timeline, the Exarch would still already be long established as the leader of the Crystarium. He would still be desperately trying to reach us - and he would fail.

Question: If nothing about his actions changed, and nothing about our actions changed—and I don't see why they should, since nothing about his actions changed—why on Earth would there be any difference between the "bad timeline" and the "good timeline" under the model you're proposing? From my point of view, both should arrive at the same conclusion: Either the Exarch succeeds and creates a paradox in which the future he came from can never have existed, at best making his point of existential origin the moment he arrived on the First and at worst meaning he himself shouldn't exist, or he will always fail to bring us to the First, leading us to die in the war against Garlemald, leaving him trapped in a causal loop in which his time traveling led to the events that begat his time traveling.

No matter how you slice it, you're getting paradoxes under this model, whether they're consistency paradoxes or bootstrap paradoxes. There is no clean solution to avoiding them short of saying "Well, I don't want that to happen", which is the impression I'm getting.

Under the model I'm proposing, there is a clear, definable difference between the bad timeline and the good timeline by this point: There is no Syrcus Tower on the First in the "bad timeline", because G'raha never arrived there with it. There is one in the "good timeline", because G'raha arrived there with it. The spontaneous existence of matter in one timeline, but not the other, is the point of divergence.

This example doesn't make sense because it picks a point where there's no reason for things to differ. There's no reason for G'raha to partly follow the same path of actions then arbitrarily stop and do something else.

And there's no reason for the WoL to partly follow the same path of actions, then arbitrarily stop and do something else either. That was the point I was trying to illustrate, so I'll restate it: Without an outside event to influence the choice, there can be only one outcome in this chain of events. We know what our timeline looked like. We don't know what the bad timeline looked like at the same point in time, but if the point of divergence is not Syrcus Tower arriving on the First in our timeline, then without a further outside event, there is no reason for anything other than what we experienced to happen. Meaning there's no reason for the Scions to not get called over in our place. No reason for us to not get called by the Exarch in the middle of our duel with Elidibus. No reason for Estinien to not rescue us, and no reason for us to not seek out the object indicated to us by the Exarch, whereupon he has no reason not to successfully summon us to the First. And eventually we must reach the conclusion that there was never a reason for the Eighth Umbral Calamity to come to pass, because there was never a reason for us to fail to stop it.

Unless we're talking Chaos Theory, which is beyond my understanding save for the Butterfly Effect: The future is inherently unpredictable due to the human mind being incapable of perceiving the full range of conditions that can affect it. Even something that looks like a sure thing can simply fail to happen for no apparent reason at all. In that case, a time traveler could travel back in time an infinite number of times and try to perform the same set of actions in a row, and every time the end result would be a unique outcome due to conditions outside his ability to control or understand. Which is very hard to visualize, but I'm assuming it would resemble one of the Hecatoncheires.

Obviously, I would find such an interpretation to be immensely unsatisfying—I prefer stories to be driven by the actions of characters, not the infinite possibilities of happenstance.

They only need to break apart when the current situation is no longer compatible with that previous version of history.

Okay, question: What is the difference between a timeline in which G'raha arrived on the First, but failed to prevent the Eighth Umbral Calamity as he knew it, and a timeline in which G'raha never arrived on the First, allowing the Eighth Umbral Calamity as he knew it to unfold? Keep in that the first timeline mentioned in that question is strictly hypothetical. That is to say, I don't believe it actually exists, and I'm only using it to demonstrate my point.

My answer to that same question: There is 100-n years of history on the First in which G'raha meaningfully affected the lives of those around him in one timeline, and 100-n years of history in which he wasn't there and thus couldn't do so. The fact that both timelines lead to the Eighth Umbral Calamity is completely irrelevant: They still take place in substantially divergent histories.