So, I'm by no means a lore expert, but I'd like to share a tougth based on the little I know, and to hear possible reasons for wich this might or might not be true or possible. Also I'm sorry if someone already said this.
Basically, Alduin and the Dragonborn are two aspects or incarnations of Akatosh, the God who controls time. If I understood correctly what the Greybeards and Paathurnax said, Alduin's task is to periodically destroy the world and regenerate it. I speculate that the Dragonborn's task is to slow down Alduin to ensure that the mortals have time to actually enjoy the world before it's destroyed, but that's not relevant. Akatosh is also depicted as a dragon or snake that eats its own tail, and that's a symbol of eternity and cyclic time.
On the other hand, the Thalmor are an Elven faction that wants to do something like destroy the whole concept of the world, like erasing it from the realm of possibilities. This is because the mortals (both Elves and Men) are actually the descendant of Immortals (like, Aedra? I know the ones who didn't became mortals became the Aedra) who lost immortality when Lorkhan tricked them into creating the mortal world, and they (the Thalmor) believe that they have to destroy the existence (that binds them in a "flesh prison") to regain their goodhood.
Now, it seems to me that Akatosh periodically destroying the world in the form of Alduin is part of this Existence that the Thalmor want to destroy. It's like Alduin doesn't actually destroy anything, he just disassembles the world and reassembles it for a fresh start.
My theory is that Akatosh created Alduin in order to prevent the mortals from figuring out a way to actually erase the world. Like, if every ten tousandish years the world is resetted, the mortals who would like to ascend to goodhod by erasing the concept of existence would not have time to figure out a way to do it. Like, if the Dragonborn was defeated in Skyrim, Alduin would have eaten the world, Thalmore included, and a new one would have born, presumably with no Thalmor for a lot of time. And when a new Thalmor-like faction would have emerged, Alduin would have returned, in order to "reset" the world again.
But why would Akatosh do that? Why he wants to prevent the mortals from regaining their immortality? I don't know that, it may be because some of the beings that lost immortality actually were ok with that, and they choose to follow Lorkhan and praise him as a god. They were the ancestors of the humans.
This theory is also supported by the
Prophecy of the Dragonborn, I think. According to that prophecy, Alduin is only supposed to wake when the last Dragonborn Emperor is dead and most of the Towers (that are at least speculated to be the pillars that hold existence up) are damaged or destroyed. This would be because when this happens, the world is more likely to be erased from existence, so it is in need of being "resetted" by Alduin.
But in Skyrim the Dragonborn actually destroys Alduin for good. I think he's called the Last Dragonborn for, with no Alduin, there is no need of a Dragonborn, but also because the ethernal cycle that prevented the mortals (in this case the Thalmor) from erasing the world from existence is now broken and there is nothing certain in the future. Like, everything since now was part of a cycle or "granted" by a divine plan, but now nothing is certain, the divine plan has failed, and the world could come to a definitive end by the hands of the insane Thalmor.
This also possibly ties with a TES VI theory
Sorry I know it's TES6 megathread only, but it's just a minor thing. Months ago I read a post here on Reddit (sorry, I can't find it or link it) that said that since Daggerfall every "main ally" of the player in a TES game was somehow linked to the main antagonist of the next game. Like: the Numidium in Daggerfall is the weapon of the Emperor, pg's main ally (and a subject, and a friend), and in Morrowind it's the weapon of the main antagonist. In Morrowind the pg is helped by Azura, a Daedric Prince, and a Daedric Prince is the villain of Oblivion, in wich you are helped by Akatosh, and Alduin is an aspect of Akatosh…
So if the villains of TES6 are indeed the Thalmor, who want to destroy the world, the Dragonborn having actually helped them by killing Alduin follows this trend.
Alduin is supposed to periodically destroy the world and recreate it, in order to prevent anyone that, as the Thalmor do, wants to permanently destroy it in order to regain their lost goodhood.
Also, sorry for my English.
Source: Original link
© Post "Theory – The Last Dragonborn might actually have helped the Thalmor ending the world" for game The Elder Scrolls.
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