WINNER!! 
personally I think Nasser would destroy Kai from the front Nasser bigger more conditioned, muscles flow
as for back I don't even think that Kai has a good back but he beats no back Nasser
and side I think that would be close, Nasser has some structural flaws but he is way harder then Kai.
but overall who knows, nasser seemed to always be pushed to 2nd or 3rd because he had more flaws then the rest.