(Insert Morrowind & Tribunal storylines here.)
The Nerevarine became grand asskicker in Morrowind, but now was chosen by Hircine to participate in the Bloodmoon. The Nerevarine did all that stuff that he/she does throughout the questline up to fighting Hircine. He/she chooses Hircine's aspect of Guile, which is the hunter's ability to outwit its prey. This turns out to be a mistake...
...Nerevarine beats Hircine at his own game, or so he/she thinks. As Hircine falls, he freezes the Nerevarine in place to keep as his trophy. This is sure to get the attention of other gods.
The Nerevarine is then released after around 200 years, in the snowy mountaintops of Skyrim. As the Nerevarine descends down the mountain, he/she is stopped by guards. They take him/her in, and the Nerevarine learns he/she will be executed for crossing the border into Skyrim. This was Hircine's trap all along, to have the Nerevarine executed by mortals, so that he may arrive to take the remains as a trophy. Mephala, the Webspinner, weaver of fate, cut a deal with Hircine to make things more sporting. Mephala had wished for the Nerevarine to be released from prison by some strange twist of fate that would charge the Nerevarine with another destiny. The Nerevarine would be made to slay dragons and decide the fate of the province of Skyrim.
As for the story of the Nerevarine going on a trip to Akavir, that is just the new Madgod's first order of business; making the world believe the delusion that the Nerevarine is no longer in Tamriel.
Just brainstorming here. Feel free to share your thoughts and theories below!
