Silvertear Skies plot hole

[Nalien]

The aetherial seal at silvertear lake prevented primals from being summoned so it couldn't have existed during the allagan era when summoning was rampant.

That's the main reason I don't think it actually was a seal, it was just Allag doing what they do best; Sealing Primals. They had Bahamut off in a space station, the Warring Triad up in Azys Lla, and Tiamat warns us that there are many more Primals sealed away by the Allagan elsewhere, yet were do we ever encounter this? Perhaps Odin and Eureka can factor into that, but still... Given the proximity to Crystal Tower, the heart of the Allagan Empire, it makes sense to me that there'd be a FFVI style Magitek Research Facility nearby containing (sealing) many other Primals.

It's entirely possible Hydaelyn sealed them away, but that creates more questions IMO; How did She seal them? Why hasn't She sealed them again? Meanwhile, we know the Allagan went on a Primal sealing frenzy. We know their capital was at Silvertear. It just fits.

Perhaps it's just the trailer being abstract, but what we see also implies to me that Ifrit and Titan (the only two we clearly see IIRC) themselves were sealed there; Physical Primals were sealed there, rather than the seal being some sort of off-switch on summoning.

Silvertear itself is important enough that Hydaelyn forged a covenant with an alien entity to grant him and his brood a haven in exchange for protecting the seal over the lake.

My only issue with this is that he didn't protect the Lake... He seemingly let the Allagan set up shop right there, and he out right nuked any "seal" that was in place there with the Agrius... He attacked the Garleans why? What knowledge of any "seal" did they have? Their motivation was purely driven by conquest, with a side helping of digging up and copying Allagan technology. The biggest Allagan find being buried right next to the Lake... The biggest Allagan find the Garleans already attempted to recreate at Bozja Citadel... Heck, Crystal Tower was even sealed in its own little time bubble by Amon...

It all just fits in my mind, meanwhile everything else just seems like myth. There are enough connections with Silvertear, the Allagan, and Garlemald, and even Primals. Meanwhile this mythical seal, this wellspring of aether? It's never been explored in the slightest, while alternative explanations pile up...

What makes you think Midgardsormr could have stopped the Allagans from setting up wherever they wanted?

If it was his job to protect the Lake because of "reasons", then I expect him to have at least tried to stop the Allagan. Instead we have absolutely no account of that, so I guess he just failed quietly? Then he failed once again when he nuked the seal in 1.0s trailer? Then he gives us sass in 2.5?

Nah, I don't buy that... I think his covenant with Hydaelyn effectively made him the first Warrior of Light, so he had to take cryptic orders from Hydaelyn like we have (also grants him significant WoL-seniority to explain how he could seal our Blessing). He wasn't guarding the Lake for every era, that simply became his new job after the Allagan Empire fell, and a failure to record history between Calamities resulted in the mythology we currently have. He has "always guarded the Lake", because there was no recorded history post-Calamity. Silvertear is the "wellspring of all aether" because... It was important at some point, right? Yes, when it was the center of the Allagan Empire, when Crystal Tower was the "wellspring" of the entire Empires energy needs...