Board Thread:Lore Discussion/@comment-103.193.59.119-20170508025131/@comment-6326997-20190129045956

The player character is the Last of Dragon's Blood. No more will follow him, unless Bethesda specifically changes the story and rewrites everything (or creates a Dragon Break).

Secondly, Alduin is not all-powerful. The Dragonborn was important to his defeat in the Dragon Crisis, but he can still be defeated by many other beings such as the gods, daedra and possibly some mortals such as the Neravarine.

Thirdly, if Alduin returns it will signal an end to the world. Or at least this Kalpa. If he returns then either the world as we see it will have fundamentally changed, or been destroyed and reborn anew. At anyrate, the destruction of Tamriel is similar to the myth of Ragnarok. If the gods die, they will be reborn. If this Kalpa ends, it will birth anew.