The Dovahkiin stood before Alduin's flame... and persevered. The stocky Nord swung Volendrung a final time and cracked the Old God's skull open like an egg. Bone and brain matter flew everywhere as the Dragon God died with a final defiant roar. The massive black corpse of Alduin crashed to the ground with a booming noise that shook the earth.
The Dovahkiin dropped to his knees, exhausted. The battle had been long, and Alduin had been ridiculously resilient to his blows, despite Malacath's blessings. "Talos above... I need a rest." He fell onto his back and stared up at the sky as Alduin's ancient began to flow into his body, imparting knowledge, wisdom, strength ... and anger. That wasn't normal, he thought as he went unconscious.
Yet, all was not well in the plane of Oblivion. Akatosh looked upon his eldest son's body, and wept tears of anguish and sorrow. Kynareth and Talos smiled as their champion put an end to the suffering of their people. Malacath sang a great ballad about his mighty hammer Volendrung and the champion who wielded it against the son of the God-King Akatosh and smote him upon the mountain side.
The Daedra laughed, all had dealings with the Dovahkiin at some point or another and they had had a lot of fun watching his progress, especially Sanguine and Sheogorath. All were happy, save Mephala. She was furious. The Dovahkiin had taken up her Ebony Blade and then abandoned it in a chest in Vlindrel Hall. She had whispered to him to kill that pathetic Housecarl of his, Lydia to gain power beyond his imagining and he ignored it.
She hated those who took the high ground. It wasn't even as if he was a priest of Arkay or some other self-righteous dolt. He had bashed an old man's brains in to work for Molag Bal. He had eaten human flesh to gain that disgusting Namira's favour. The worst was hiring that mage and then giving him to Boethiah as a sacrifice. He was a complete hypocrite!
She knew Azura and Nocturnal were laughing at her behind her back, and it was only a matter of time until Hermaeus Mora found out, nosy busy-body as he was. She didn't like this feeling of rejection and humiliation, from a blasted mortal no less! In her rage, Mephala did not see that the Dovahkiin was already dying. No human soul, not even the Dovahkiin could sustain such a huge amount of power in such a short space of time.
Watchful Hircine was the only one who picked up on this, and he was annoyed. The Dovahkiin was less his champion, than a minor avatar of his due to his wolf blood. Hircine knew the other Daedra would lose interest soon and the Dovahkiin could not survive on His will alone.
So Hircine decided to help the Dovahkiin in the best way possible. He turned him into the statue of a great hound, which sat upon a mountain top beside the desiccated skeleton of his greatest enemy for the centuries until Alduin's power could be absorbed.
Over the next few thousand years, the landscape shifted and changed. Atmora drifted south out of the cold and people began to live there again. The Khajiit and Argonians fled to the southern lands, beyond the reach of bigoted human lords. The Dwemer returned, changed beyond recognition and with no memory of what their race had accomplished and rebuilt an empire beneath the ground.
The bigotry sparked by Ulfric's rebellion drove the elves to foreign lands where they eventually became a single people and their magic granted them a lifespan similar to immortality. A lot of what was the Empire and Skyrim fell into disarray after the assassination of the Emperor by the Dark Brotherhood. Continental shift buried much of the eastern lands underwater, including the Imperial City.
The Redguards fled across the ocean created to a peninsula from Hammerfell and called it Rivain. The Orcs found favour with both Malacath and Jyggalag, who sent them north beyond Atmora in their thousands to change in a new people under a single faith and banner, the Qunari. The magic in the blood of the Bretons was corrupted by a massive wave of painful nightmares spread by Vaermina until it became connected to Oblivion, which by then was called the Fade. This connected mages to Oblivion in a way never seen before, and their darker sides became manifest, as demons.
Belief in both Aedra and Daedra fell away in most parts of the world, most humans eventually becoming converted to the worship of a single deity known as the Maker, had surprised the two pantheons and their followers by gaining strength inordinately quickly, sweeping aside all opposition under the banner of His Bride, the Prophetess Andraste.
The wars that followed and the subsequent destruction of the Dales angered many of the Aedra and Daedra, whom the elves had been worshipping under new names for at least two thousand years. The only thing that annoyed them as much was the actions of the Falmer, or at least what had been the Falmer.
The dragons had dwindled after the death of their leader Alduin. Many died, but those who did not either fled to Paarthurnax, who sat at the top of The Throat of the World, or went underground and went to sleep again. The Falmer sometimes came across these sleeping dragons and tried to domesticate them, but failed hilariously. Until Namira and Peyrite formed a pact.
The Falmer became infected with a horrific, corrupting disease the humans later called the Taint. They changed and twisted into vile creatures who eventually subdued a dragon and corrupted it as well. At the same time, some ambitious mages attempted to gain access to a part of the Fade that couldn't be accessed by mortals. The Maker threw them out of the Fade into the pit of the Falmer, who turned them into the first Darkspawn. They in turn corrupted and spread underground, reaching the empire of the Dwarves.
Eventually men and women sacrificed their lives to become Grey Wardens, who took a little of the taint into themselves, shocking and amusing the Daedra, to gain an awareness of the Darkspawn that in the end allowed them to destroy the Archdemon and drive the Darkspawn back underground. This happened another three times, each more destructive than the last.
Empires rose and fell, plague and famine swept across the land and wars killed millions, but through all this the Dovahkiin slept on, his legend nigh but forgotten and the hound statue that contained him brought to a gilded prison in the middle of a lake, where a young mage who would change the fate of the world, but not in the way she could have, was being led through a cellar by her best friend and his new girlfriend.
This is not the story of the Warden who saved Ferelden. This is not the story of a hawk who took flight. This story is the return of a legend to the world. The return of a hero. In their tongue he is Dovahkiin. Dragonborn.