And that is my cue. I promised earlier to give my full assessment on the nature of Alduin, and so here it is, along with my thoughts on some other new perspectives on long-held lore ideas referenced in Skyrim.

Firstly, I feel that on the surface, the Skyrim main quest is somewhat simple, if not as much as Oblivion. You have a Dragon-God harbinger of the apocalypse, a Civil War and some elves are putting on the reich. Unlike Oblivion/like Morrowind, it is a traditional hero-arc story. While much (but not all) of Morrowind's complexity was contained entirely within the game, about half of which in the main quest and half elsewhere, much of Skyrim's lore glows only when overlaid on a picture of the whole series. There's your simple shape and complex hole. The lore of Alduin, Sovngarde and the Dragons was given partially in fragmentary form in other materials and now, in addition to Skyrim, the complete (or as near to it as we're going to get) picture can be found.

On the Alduin/Akatosh Dichotomy:

I wonder, does rewriting Tamriel's history also effect Akavir, Atmora, Aldmeris, Thras and Pyandonea? The Dragon Cult was supposedly benevolent in Atmora, despite Alduin being the World-Eater. If they became cruel and oppressive tyrants, as did Alduin himself, when and not before they first reached Tamriel, then I may have an idea:

Alduin is, and was, a force of nature, not a force of evil as he is seen today. So while he will end the world, the knowledge of the Atmorans that in destroying the world he would birth the next made him simply a force to be endured and respected. When he came to Tamriel, a place where Akatosh had been written into history for the first time in the kalpa cycle, Alduin was also rewritten to be an active, rather than passive, aspect of time-as-destruction and therefore evil, choosing to enslave humanity until he would devour the world and the Akatosh-aspect would help to restart it with Magnus and Shezzar and the rest. So, with he and his priests suddenly tyrannical warlords, humans rebelled. Even though Ysgramor had the Shouts from Kyne as a natural process, the creation of evil Alduin rather than passive Alduin meant that humans also first received the Thu'um from Kyne along with Paarthurnax during the Dragon War. Because humans are not as severely effected by Temporal fluxes as Dragons, Dragons do not remember a timeline where Alduin was passive and the Great Dragon rather than his firstborn, while humans, who can remember both a timeline where Vivec was born an elf and where Vivec was always a god, can also remember both a time when Alduin was wholly Akatosh and, as we see him today, when he is but one-third an aspect of the entire God of Time and is in this lesser aspect his own son.

I love the Merethic. we have the words to construct all the ideas without wholly killing them, unlike the Dawn where things were all strange and wonderful, but it is all still strange enough to have multiple incompadible timelines both being true.

How Alduin stopped being Auriel and became Akatosh-son-of-Akatosh

Paarthurnax states that Dragons, being so closely linked to Akatosh ("of Akatosh," you might say) are even more vulnerable to temporal fluxes and Dragon Breaks than other species. Therefore, when Alessia created Akatosh, they were rewritten.

Alduin is still an aspect of Time, as the unrelenting force (pun intended) of time wherein all things are born, die, and born again. However, where before Alduin was Auriel, who were both simply the god of the End, the creation of Akatosh, and the relatively new idea of morality and gods being mentioned in the same breath, caused a massive mythic and historical rewrite. Alduin became a force of pure annihilation, an otherworldly Dragon of unimaginable power that can not be escaped by the living or the dead. Auriel we have not yet seen, but my speculation based on Esbern's dialog of the Thalmor wanting the world to end "on their terms" makes me think that the Auriel aspect may only destroy humans and then raise all "true" elvenkind. Akatosh, being after thousands of years of intermittent war, conquest and rulership by the Empire of Man the most widely worshiped of the three, became the chief god, the first and Allfather of the dragon-kind, a preserving force of benevolence.

"'kay, we already went over that before release," you may well be saying about now, "this is pretty much given."

This is really the only place where the perspective has shifted: where before we looked at the Alduin/Akatosh dichotomy as similar to Hinduism, where one god has aspects of preserver and destroyer with Shezzar filling the creator role, the historical rewrite has caused Akatosh, the preserver aspect, to be the God to Alduin's Jesus, in the Catholic sense of Alduin being both entirely Akatosh the Time God and entirely Alduin, the individual dragon who is the son of his own God-aspect.*

So really, it just adds another half-twist to what we already knew and gave us measureable effects on what the creation of Akatosh has done to the order of the world.

How Does Shor Fit In?

I have, since Ulfgar the Unending, wondered at Sovngarde, and if (or how) it relates to the Dreamsleeve, along with afterlives related to certain soul-traffiking Daedra like Clavicus Vile and Molag Bal. I think, at last, http://www.imperial-library.info/content/shor-son-shor-full and Skyrim together have given me my answer, to Sovngarde at least.

My hypothesis was, with Shor being an individualistic god of an individualistic people, perhaps Sovngarde, either alike to certain Daedric realms or alone among the recorded afterlives, was in fact not an semi-illusory way of souls that have not yet dissolved back into the whole to process the massive aliein-ness of the Dreamsleeve, but is, instead, the plucking of souls from the cycle for a time.

The reason I did not pursue this before was because, simply enough, there was no reason within the lore that this might be. It would have been a dead end leading to no interesting little quirk in the tapestry of the tale. Now it is. The Awful Fighting from Shor son of Shor plainly involves humans as well as gods, some of whom die. In Skyrim, when you reach Sovngarde Ysgramor and the three Merethic heroes of the Dragon War are still individuated personalities, even after thousands of years. The quest journal labels Sovngarde as being alike to Valhalla, where the heroes await the final battle. So, my assessment is twofold:

Sovngarde is a conduit, by Shor, to rip souls, never enough per kalpa to be missed, out of the Dreamsleeve cycle. Only the worthiest souls, those who will be the human warriors in the Awful Fighting at the end of the kalpa, will be taken and kept from dissolving back into the massive "Oversoul" of the Dreamsleeve. That is why Shor refused to let the Hall empty at the weakened Alduin. If the Awful Fighting began with Alduin weakened by his aspect-split and by his wounds at the hands of the Dovahkiin, then there would have been no new kalpa when the Awful Fighting ended again, and all Shor's work as Shezzar would have been undone by the very act of his final victory.

There is, having finally finished Skyrim's main quest last night, my assessment of the nature of Alduin and a succinct explanation of the new metaphysical lore as I see it.

*It should be stated as a disclaimer that this is used as an example of what real-world theological ideas can be best used to explain the nature of Tamriel when lacking a secondary interior example and is not an invitation to discuss real-world religions as forbidden by forum rules.