Crowley
I've never met anything without a soul that wants one, though. I just sorta figured that went with the whole soulless territory. Not that there's all that much of a territory for soulless humans considering it's pretty much an afront against nature and just wrong on levels that I didn't even know existed.
Oh! Right. Well, I just so happen to have an Orb of Thesulah, which offers a safe doorway to the ether for the soul to pass. The curse sort of activates the orb.