Board Thread:Lore Discussion/@comment-13446185-20130727042242/@comment-212.242.237.36-20130727231702

I think that Dragonborns are given their powers at birth (when they are born). Miraak walked Tamriel at the time of the Dragon Wars, so it is possible that Akatosh choose a random (more or less) individual to become the Dragonborn, who would fufil the Akaviri prophecy, and slay Alduin. However, Miraak choose differently (The last Dragonborn can also choose not to kill Alduin), and sided with the Dragons/Hermaeus Mora.

If being Dragonborn is in your blood (as suggested multiple times in the game), I don't think that Akatosh can just take it away. Especially not when Miraak was hiding in Apocrypha, which should be waaay out of the Divines' reach.