I went back and forth on whether to make this a post or a thread but I'm just going to shove it here. I was thinking today about an old conspiracy theory of mine and I think perhaps it's time to revisit it (in the vein of being wrong for fun and profit). Back in Heavensward, the Word of the Mother's speech and the Moogles possibly remembering the First Umbral Era led to me thinking about that particular event a little too much. One of the things I was stuck on was that the legends seem to be overlapping a little bit.
It is said that the Twelve left Eorzea at the coming of the First Umbral Era, ending the "Age of the Gods" and ushering in the Age of Man.
The way the first lore book phrased the coverage encouraged conflating this event with the end of a "prehistory" but something about it always sat wrong with me once people started connecting it to the pre-sundering world alone. As I pointed out then, tl;dr, the great sundering and first rejoining can't be the same event.
But let's check out that phrasing again...
It's easy to see how one might miss the forest for the trees there. However, after Shadowbringers we can (probably) safely say that the "tempestuous time of uncontrolled creation overseen by a mercurial god or gods" is actually the Ancient Era, where Amaurot thrived before the great sundering. I think the "competing theory" is actually also true, to a degree, but reflects an unnaturally created world findings its own natural equilibrium for about 2,000 years after the sundering.The First Umbral Era: The Calamity of Wind
Eorzea is characterized by elemental calamities which plunge the realm into short, yet harrowing periods of chaos known as Umbral Eras, followed by extended periods of prosperity known as Astral Eras. What then, you may ask, of the land before the first calamity struck? Drawing from the songs and writings of countless civilizations, theologians believe prehistory to be a tempestuous time of uncontrolled creation overseen by a mercurial god or gods - creation which abruptly ends with the destruction of all that exists, ultimately allowing for the rise of mankind from the wreckage. Historians and scholars of biological fields, on the other hand, claim that mankind could not have simply "appeared" and suggest an evolution of the species in the thousand thousand years preceding the first calamity. What the two groups do, however, agree upon is that modem history begins with the First Umbral Era.
My theory at the time was that there was a hitherto unrecognized era that was post-sundering and pre-calamity, and that's where the Twelve thrived. That perhaps Hydaelyn made guardians for Her children, and somehow the Ascians were able to exploit these beings in such a way that it led to the First Umbral Era, so She sent them away somehow.
I think I'd like to return to that with a new speculation about where 6.0 might be headed by combining this old theory with one of my more recent ones: Venat's coalition of Hydaelyn summoners are the Twelve. (How this fits with Azeyma/Azim is an immedate "wtf" here, I admit, but let's set it aside.)
After Hydaelyn's victory over Zodiark and the great sundering, the planet entered a new age with the victorious - and now tempered - "Counter Convocation" remanifested in some form at the helm of Hydaelyn's new world. As with the Convocation and Zodiark, this coalition perhaps even now existed only to spread Her Light. As Elidibus, Emet-Selch, and Lahabrea restored their sundered brethren to their offices and became the Ascians, they struggled against Hydaelyn's champions, and this led to the First Umbral Era.
Hydaelyn, realizing the vulnerability, sundered her own champions to save them and let them be reborn into countless lives detached from the tempered identities they would have if their immortal memories were restored. And so the Twelve were no longer with us.
But the Ascians would come again, and again, and again. We know that Hydaelyn would essentially mass-market the Echo and take any who answered the call, but I believe - just as there are rare occasions where she chooses to entrust a single champion with extraordinary power - there were also occasions where she re-unites her ancient allies as whoever they are today, and this is why history remembers them in such eras as the Third Astral or the Zodiac Braves as a group of twelve, the Twelve reborn.
It's a pretty tall house of cards, but hey, it's fun to think about.