Upon death, where would the souls of Dragon Priests and other cultists go?

Sovngarde seems to be out of the question because Shor does not take kindly to dragons feasting on the souls in his realm, much less their treacherous servants walking throughout the Hall of Valor.

Recycling via the Dreemsleeve seems to be a more likely destination though, despite it not sounding as exciting.

Or perhaps they join the with the Aka-Tusk/Bormahu.

Thoughts?

Most likely, the psuedo-eternal life that the Priests have is their ultimate destiny. The http://www.uesp.net/wiki/Skyrim:Alchemist%27s_Note of the Dragon Cult in life was obsessed with awaiting Alduin's return, and did not want Skorm to burn their bodies and prevent them from becoming Dragur. Its quite possible that they expected, like so many liches do, to live an eternal life in service to their masters.

Agreed. Dragon Priest's afterlife is exactly where you find them in game.

I think he means what happens to them once you destroy their undead bodies.

EDIT: Dargor is that link... um... meant to go to the Alchemist page? Because I'm not seeing any correlation between that page and what you were saying.

No, it wasn't, which is odd because I never even went to that page when posting the link, and the editor completely wigged out when posting the link. http://www.uesp.net/wiki/Skyrim:Alchemist%27s_Note is what I was referring to. As to your statement, its entirely possible that the Cult didn't even believe in a after life, and sought to keep themselves useful in life and death. Being made into Dragur is sort of an afterlife of sorts in of itself.

Upon losing our connection to this mortal plane, we return to Alduin's holy belly. From henceforth, we shall be excreted as kings and lords, in the new kalpa's wake.

Praise be.

Dreamsleeve sounds likely, at least compared to other options.

Come bearing Nine Masks, and enter Lord Alduin's Demesne...

Wait a minute.

Your theory reminds of Mankar Camoran and his Paradise.

Though at the same time, I do like the idea that they join the Aka-Tusk, though I have no evidence to back it up.

You only go back to Aka if you're a Dragon, because that's your AE. I suppose it is possible to become so strongly aligned with Akatosh that you go to his plane when you die, but I can't think of any other way.

So with this theory, after they are killed in the Draugr form they cease to exist anymore?

After that, their souls are probably recycled in the Dreamsleave.

Or whatever happens to any other unaffliated mortal in Tamriel. The Priests probably believe that their and the entire worlds fate is to be devoured by Alduin, so an afterlife is practically pointless. None are safe from his maw.