Okay, i know this fight will never happen what with the whole James being dead thing. But if James and Demetri ever did fight who would win?
James was a hunter as a human, he was the best of his time. Then he became a vampire and when hunting humans got boring he actually started hunting his own kind for sport, he even hunter a werewolf (Child of the moon) and killed it! Obviously he must be a good fighter as well as a tracker to be able to fight so many of his own kind and survive, and his senses are said to be above vampire level, his power also allows him to have a gut feeling of his prays next move or where they will go to hide.
Demetri on the other hand is the greatest tracker in the world! No one save Bella is able to hide from him, his power allows him to track from anywhere on the planet by catching the scent of a persons mind. He is always at the spear head of the Volturi guard missions and he has been fighting a lot longer then James has so he has more experiance.
So who do you think would it be?