A Dragonborn or Dovahkiin is a mortal blessed with the Blood and soul of a dragon by Akatosh , the Father of Dragons and chief of the Divines. Any subject of the Empire prior to the Fourth Era would say they were ruled by the "Dragonborn Emperors", but very few understood what that title meant. The Dragon God imbued Alessia's line with blood from his own heart, initiating a sacred compact which kept the Dragonfires lit and Oblivion's influence barred from Mundus , so long as those of the Dragon Blood wore the Amulet of Kings. Indeed, the title is particularly associated with Tiber Septim himself, perhaps because he made notable use of the thu'um in his early conquests. Eventually, the last of the Septim bloodline sacrificed himself and the Amulet to permanently restore the liminal barrier. The Dragonborn plays a prominent role in the legends of the Nords of Skyrim , who tell tales of heroes who would "kill dragons and steal their power". The Greybeards of High Hrothgar warned that many of them met their downfall because the ease with which they learned the thu'um made them arrogant. The Greybeards attempt to inculcate the values of the Way of the Voice , and strongly disapprove of the violent use of thu'um in general, but tolerate it among those who have been blessed by the gods.
The Last Dragonborn. Not much is known about his childhood, his story begins as a prisoner of the Imperial Legion. He tried to cross the border, and was captured at Darkwater Crossing as he ran into Ulfric Stormcloak and his men. The Imperials saw the Nord as a Stormcloak, put him in binds and placed him in the cart with a horse thief, a Stormcloak soldier and Ulfric Stormcloak himself. The Imperials took the prisoners to Helgen, ready for a swift execution and an end to the rebellion. As the Last Dragonborn was pressed on the chopping block, a roar deafened every sound in the town. A huge black dragon soared through the sky, and landed on a tower. The beast shouted, and the sky opened up. Flamig rock fell, stopping the execution and causing chaos.
One of the hallmarks of The Elder Scrolls series is that the player character is referred to with a title. In the latest mainline instalment, The Elder Scrolls V: Skyrim , the player character is known as the Last Dragonborn , the prophesied hero destined to defeat Alduin at the end of the world. Yet is the player character of Skyrim truly the last Dragonborn? Dragonborn or Dohvakiin in the universe of The Elder Scrolls are individuals born with the soul of a dragon, granted to them by the Divine Akatosh. The entire Septim line , which dominated the Cyrodiilic Empire throughout the entirety of the Third Era consisted solely of Dragonborn. So reliant was the Septim Empire on the installation of a Dragonborn on the Ruby Throne that when this tradition was threatened, it was enough to begin the Oblivion Crisis.
I find it hard to believe our character is the last dragonborn because of the prophecy: The World-Eater wakes, and the Wheel turns upon the Last Dragonborn - it exactly says it plainly. When the world-Eater wakes The prophecy states that When the Snow Tower lies sundered, kingless, bleeding - which hasnt happened yet and the plain fact that your character himself mentions that he didnt absorb Alduin's soul and the NPC mentions that Alduin might get to return at the end of time to fulfill his role. All of these are valid reasons to say that the Dragonborn character is not the last. I think it just means he is currently the last dragonborn plus all his kids so far are adopted.