Alduin

"And the Scrolls have foretold, of black wings in the cold,""That when brothers wage war come unfurled!""Alduin, Bane of Kings, ancient shadow unbound,""With a hunger to swallow the world!"Alduin, also known as the World-Eater and the Twilight God to the residents of Skyrim, and to the ancient Khajiit as Alkhan, is an immensely powerful black Dragon that serves as the primary antagonist of The Elder Scrolls V: Skyrim. A being of pure malevolence, he is depicted by the Nords as the end of time, destroying the world at the end of each Kalpa so that it may be reforged for the next. He is the self-proclaimed First-Born of Akatosh and is commonly believed to be an aspect of Akatosh. His name, like those of many dragons, can be separated into "Al Du In", which in the language of dragons translates to "Destroyer Devour Master".

In his Khajiiti depiction, Alkhan is a Wandering Spirit also known as The Scaled Prince, and the Firstborn of Akha. Ancient Khajiiti texts claim that he is a demon of fire and shadow who grew in size with each soul he ate, and that he hungered for the crown of Alkosh, the Dragon King of Cats and the Khajiit's equivalent of the Divine Akatosh. Alkhan was slain by Lorkhaj and his companions, but it is said that he will one day return along the Many Paths.

History
According to the dragon Paarthurnax, Alduin was once considered the greatest of Akatosh's creations. According to the writings of the Archmage Shalidor, dragons have existed since the dawn of time, but were wild until Alduin created their civilisation. He held a position in the Nordic pantheon as the dragon god, opposed to Kyne, the hawk goddess and chief deity of the ancient Nords. Where Kyne was seen as the bringer of life, Alduin was feared as a harbinger of death and destruction. Such beliefs would cause Nords to be disturbed by the fascination of Imperials with their own version of Alduin, Akatosh, as late as the Second Era. By the Fourth Era, this view will have changed, and many Nords will claim that foreigners created the myth of Alduin being the Nordic version of Akatosh out of ignorance of Nordic oral traditions.

During the early Merethic Era, the ancient Atmoran people; ancestors to the modern Nords; worshiped numerous animal totems as avatars of their gods, which would become the Nordic Pantheon - the hawk (Kyne), wolf (Mara), snake (Orkey), moth (Dibella), owl (Jhunal), whale (Stuhn), bear (Tsun), fox (Shor) and dragon (Alduin). For reasons unknown but believed to be due to Alduin's urgings, the people of Atmora and Skyrim would come to deify dragons above other animals, leading to the rise of the Dragon Cult as the prominent religion of ancient Nordic culture. Some consider that Alduin's desire to be worshiped by mortals led to him forsaking his role as World Eater out of arrogance. Alduin was a cruel leader, both to his fellow dragons and especially to the ancient Nords, and many would be enslaved and sacrificed to him and his siblings by the Dragon Priests, who's authority was seen as equal to kings.

Alduin's chief lieutenant during this period was the dragon Paarthurnax, his younger sibling, who is said to have committed unspeakable atrocities against mankind. However, at the behest of the goddess Kyne, Paarthurnax turned on Alduin, teaching the humans how to wield the Thu'um; dragonkind's ability to turn words into weapons; and granting them the chance to rebel against their overlords. This conflict would come to be known as the Dragon War, and would end in a climactic battle between Alduin and the three Nordic heroes, Felldir the Old, Hakon One-Eye and Gormlaith Golden-Hilt, atop the Throat of the World. The three heroes would create a new Shout known as Dragonrend, which they would use to subdue Alduin, before using an Elder Scroll to banish him. Whilst they believed that they had defeated him, in truth, they'd only sent Alduin forward in time.

A prophecy, found inscribed on Alduin's Wall in the hidden Sky Haven Temple, warns of the return to Alduin,. This prophecy also states that the Last Dragonborn will come forth to stand against Alduin.

The Dragon Crisis
As was foretold, Alduin resurfaced during the Skyrim Civil War in the year 4E 201. His first action was an attack on the village of Helgen, as an announcement of his return, before visiting the ancient dragon burial mounds across Skyrim to resurrect his subordinates. It would be revealed that one of the survivors of Helgen was the Last Dragonborn, the only person able to defeat the World Eater and the only one who could truly kill a dragon, by absorbing their souls. With the guidance of the dragon Paarthurnax and the assistance of both the Greybeards of High Hrothgar and the last remnants of the Blades, the Dragonborn was able to defeat Alduin, forcing to retreat to Sovngarde, the Nordic afterlife, to regain his strength. The Dragonborn would follow Alduin here and, with the help of the three heroes who defeated Alduin in the past, finally put an end to the wyrm's tyranny.

It is commonly believed that the Dragonborn killed Alduin during this final confrontation. Some even assume that this victory signals the beginning of the final Kalpa, as the dragon's death means there's no one to bring an end to time. However, despite defeating Alduin, the Dragonborn never absorbed his soul. This suggests that he will return one day to fulfill his role as the World Eater.

Abilities
As a dragon, Alduin has the ability to fly due to his natural wings, and the powers of the Thu'um, of which he commonly uses the Fire Breath, Frost Breath and Unrelenting Force shouts, as well as a much more powerful version of the Storm Call shout that calls forth a meteor shower rather than a lightning storm, a unique shout that can resurrect dead dragons and a shout that summons forth a mist, designed to snare the souls of those in Sovngarde. The names of these shouts are unknown, but it is known that the resurrection shout is made up of the words "Slen Tiid Vo", which translate to "Flesh Time (Opposite of)," whilst the soul-snare shout is made up of the words "Ven Mul Riik", which translate to "Wind Strong Gale". In addition, as the World Eater, Alduin has the unique ability of being immune to the Dragonborn's ability to steal the souls of dead dragons. Killing Alduin sends his soul back to Akatosh, to await the end times. If ancient myths are to be believed, Alduin's ability to steal souls isn't limited to the dead. According to an ancient Nordic myth, Alduin was summoned by Orkey as part of a plan to turn the Nords into children. During this, his ghost "ate" the age of the entire Nord population down to six, only stopped by Shor on the request of King Wulfarth.