I'm having trouble understanding this all at the moment but to the best of my knowledge, Roxas isn't a Nobody.
Ven's heart became a part of Sora's at the end of BBS. When Sora lost his heart in the original KH, he regained both his heart and his body rather quickly afterward with help from Kairi.
That being said, a Nobody is the heartless shell left behind when one loses their heart to darkness. However, Sora left no body behind when he became a Heartless because he reclaimed it. Would that not go so far as to say that Roxas was not a Nobody born of the separation of Sora's heart and body, but the split between Sora's and Ventus's hearts?
Ven's heart, once connected to Sora's, might have been lost when Sora briefly lost his own heart, the tie severed by darkness. Ventus's heart may very well have then gone off and created a body for itself out of the memories of its previous life (that life being Ventus, explaining their resemblance). When the memories were used up, they were lost and a being shrouded in oblivion came into existence. This would explain why Roxas had no memories of his previous life while other Nobodies could remember perfectly what had transpired before they lost their hearts.
Just thinking out loud, feel free to correct me where I'm wrong because at this point I'm pretty lost.
P.S. Something more to think on: Nomura once stated in an interview that there are as many Keyblades as there are strong hearts to wield them (citation needed). If that's the case, and Roxas was never a Nobody in the first place, would that mean only beings with hearts could wield the Keyblade? [Ansem SOD, a Heartless, wielded the Keyblade to people's hearts - but only after possessing Riku's heart.]
Ven's heart became a part of Sora's at the end of BBS. When Sora lost his heart in the original KH, he regained both his heart and his body rather quickly afterward with help from Kairi.
That being said, a Nobody is the heartless shell left behind when one loses their heart to darkness. However, Sora left no body behind when he became a Heartless because he reclaimed it. Would that not go so far as to say that Roxas was not a Nobody born of the separation of Sora's heart and body, but the split between Sora's and Ventus's hearts?
Ven's heart, once connected to Sora's, might have been lost when Sora briefly lost his own heart, the tie severed by darkness. Ventus's heart may very well have then gone off and created a body for itself out of the memories of its previous life (that life being Ventus, explaining their resemblance). When the memories were used up, they were lost and a being shrouded in oblivion came into existence. This would explain why Roxas had no memories of his previous life while other Nobodies could remember perfectly what had transpired before they lost their hearts.
Just thinking out loud, feel free to correct me where I'm wrong because at this point I'm pretty lost.
P.S. Something more to think on: Nomura once stated in an interview that there are as many Keyblades as there are strong hearts to wield them (citation needed). If that's the case, and Roxas was never a Nobody in the first place, would that mean only beings with hearts could wield the Keyblade? [Ansem SOD, a Heartless, wielded the Keyblade to people's hearts - but only after possessing Riku's heart.]