Wow man, really? We had a whole debate over this on the previous talk page before someone remade the article. I guess I have to restate my reason why this is Vanitas' X-Blade:
"It has been brought to my attention that some people feel that the X-Blade should not be put under Vanitas' ownership. I feel that since it has only been wielded by Vanitas, it is ok to assume rightful ownership to him. If someone were to wield it in the future, this article will have to be changed to "X-Blade", but seeing as it has only been wielded by Vanitas, I feel it should stay the same. What are your thoughts on this?"
(directly pasted from the other page)
and LegoAlchemist has stated:
"I think that, for know, with the information that we have, we should leave it under Vanitas's X-Blade. I mean, He is the only person that wields it (Ventus not counting, because Vanitas was probably possessing his body). So until we learn it's official name, we should leave it as is."