Hmmph, I really don't like the idea of dualling him at all and doubt I'd ever really consider the idea. The sheer strength of his will to live and dark megalomania seems to lend itself perfectly to the Choatic Evil fighter that he is. Perhaps it is slightly more conceivable if one chooses the 'redemption path' for him, but I still wouldn't like it and I doubt if you asked him personally that he'd enjoy having his 'bhaal-class' purity diminished either.
Thumbs up for the idea though to generate posts and conversation. I can see the potential for roleplaying a certain way, but its not for the way I see him.