Muscles posted...
That's why we need the dragonborn to take over as king of the world
Considering how Bethesda tends to say "Fuck it, you completed every questline and all endings somehow occurred simultaneously", you end the game as the only living Dragonborn who has effectively single-handedly won a civil war and assassinated the last surviving Emperor.
I wouldn't be surprised if Elder Scrolls VI just skips ahead a couple hundred years, and reveals that you became the new Emperor, reunited the Empire, and led a war against the Thalmor.
Of course, you also apparently sold your soul to at least one Daedric Prince because the Thieves' Guild quest was incredibly stupid, so who knows.