Alduin

"You do not even know our tongue, do you? Such arrogance, to dare take for yourself the name of Dovah!"

- Alduin to Dragonborn

Alduin the World-Eater is the Nordic God of Destruction and the main antagonist of The Elder Scrolls V: Skyrim. He is the eldest son of the main god in the series, Akatosh, and his evil counterpart. He is also the elder brother of Paarthurnax, who was his chief lieutenant during the dragon war but ended up betraying him and helped the mortals instead.

Personality
Like many typical villains, Alduin is very arrogant, a trait he attempts to counter by accusing his opponents of. Once his goal is revealed in the storyline, it is revealed that he is also misanthropic, believing that Dragons (or Dovah) are the superior species against man.

History
Long ago, Alduin was defeated by the ancient Nord heroes who used an Elder Scroll to make him lost in time and hopefully never return. Unfortunately, he ended up in the 4E 201, the time the game takes place. Taking the form of a monstrous black dragon, he sets out to destroy Nirn (the world where The Elder Scrolls take place) with the help of his servants (dragons). It is up to the player, the last of the Dragonborn, to stop him.

Alduin first appears just before the Dragonborn is about to be executed for a pity crime in the small town of Helgen. The attack coincidentally frees the Dragonborn and they escape the town alongside General Tullius and Ulfric Stormcloak.

Eventually, the Dragonborn learns of their true identity and is contacted by one of the remaining members of the blades named Delphine to actually confirm their identity. They set out to Kynsgrove, where the two witness Alduin resurrecting a dragon from the nearby mound. The Dragonborn and Delphine defeat the dragon, and the former then absorbs its soul, confirming Delphine's suspicions.

Eventually, the Dragonborn is tasked to learn Alduin's bane, a shout called Dragonrend which temporarily sabotages dragons in flight. In doing so, the Dragonborn and Paarthurnax are ambushed by him after activating the time wrap with the Elder Scroll, but the two of them manage to hold off and defeat Alduin temporarily, despite his taunts and claims of power. Afterwards he flees, only for the Dragonborn to learn from Paarthurnax that he is attempting to head for Sovngrade, the Nordic heaven to absorb the souls dwelling there.

After a conference with many heads of power atop High Horathgar (or not if either General Tellius or Ulfric Stormcloak are killed). The Jarl of Whiterun allows the Dragonborn to use Dragonreach as a means to lure and trap Alduin's second-in-command, a dragon named Odahviing. The plan works, and the Dragonborn successfully captures Odahviing. The dragon then bargains with the Dragonborn that in exchange for being freed, he will lead them to Alduin's hideout, as he never liked or trusted him in the first place. The Dragonborn agrees and Odahviing willingly leads him/her to a temple, where a portal leading to Sovngarde is guarded by two dragons and a dragon priest.

The Dragonborn manages to defeat and kill Alduin in Sovngarde, while he was absorbing souls to rebuild his strength, though was not able to absorb his soul as they did to other defeated dragons, his body incinerates in an explosion of light. When the Dragonborn asks the Greybeard Leader Arngeir about this, he remarks that Alduin may return and bring the end of the world to fulfill his destiny, indicating that only his physical body was destroyed but his soul may be allowed to return to destroy the world if the gods permit, however the exact date of his return remains shorted in mystery.

Alduin is the son of Akatosh, the chief deity of the 9 divines in the Elder Scrolls lore. In fact, all dragons are children of Akatosh. Since the Dragonborn has the soul of a dragon, Alduin could technically be the Dragonborn's brother, however this is a subjected to debate as they are also human.

Ironically, despite referring to the Dovahkin as being arrogant, it was his own arrogance that led to his demise.

Trivia

 * His name in draconic language translates into Destroyer-Devour-Master.
 * His size is significantly larger than any other dragon encountered in the game.
 * Alduin uses a unique shout called Dragon Storm Call which is similar to the normal Storm Call shout except it summons meteors instead of lightning. The words of power however are unknown to the player.