Alduin, the World Eater and first born of Akatosh, is the main antagonist in Skyrim. He is the oldest dragon and was created by the deity Akatosh. His title, World Eater, comes from the Nordic myths that associate his return with the end of the world and the coming of a new age. Lore surrounding Alduin is extensive and often contradictory. As a result many Nords mistakenly identify Alduin as Akatosh when in fact they are two separate entities. This falsehood is put to rest during the conclusion of Skyrim’s main questline, revealed in dialogue options with Paarthurnax and by Alduin himself. Alduin is not a god, it is in fact his claim to godhood that caused his brother and former lieutenant, Paarthurnax, to betray him during the first dragon war.
Paarthurnax claims that Alduin has grown too proud and forsaken his destiny as World Eater. Instead he seeks to conquer the world for himself. Unlike the other dragons in Skyrim, the Dovahkiin does not absorb Alduin’s soul upon defeating him. Dialogue options available through Paarthurnax during the epilogue suggest that Alduin’s soul may have been saved so that he may one day return to fullfill his role as World Eater.
Alduin is also able to feed upon the souls of the dead in Sovngarde, an advantage he has defended from the other dragons and kept to himself. He is apparently able to gain access to the Nord spiritual realm through the aid of the Dragon Priests. This ability may have given rise to some of the more apocryphal legends scattered throughout Nordic lore.
In the language of the Dova (Dragons) Alduin’s name is the conjunction of three words: Al - Destroyed, Du - Devourer, and In - Master.