tutti frutti. Since the two are practically indirect identical twins, this seemed like something to put up. Between the two keyblades wielders, which one of the two would you want to win a fight to the finish? I think that it would be a good fight to see, if not play. And if the two ever really met, and Vanitas unmasked himself in front of Sora, who knows (other than Nomura and co) how Sora would react to that. And for any and all major Sora fans, no offense to the short description of the poll, just a small description. Maybe we will see this fight in a future KH game, KH3 maybe.

Well, since a theory is that

Vanitas will attempt to kill Xehanort in order to get more power.

He'll come back in possibly KH3 whenever Ven gets his heart back.

When that happens, Vanitas may return and kill Xehanort

or not return at all.

Haha, I was the one who originated that theory

I am sure that the clash is inevitable. But like I said in my theory, Vanitas is likely to take over as the main villain after the Xehanort Saga. So Sora probably wont get an opportunity to fight him for a long time. But to answer your question, as things stand right now (pre-DDD and without party members) Sora would lose. Vanitas is just far too skilled.