If the nobodies are "the bodies", then Roxas shouldn't have Ven's body. Yet he does. That means he's just as much from Sora as he is from Ven (both hearts were lost when becoming a heartless).
Roxas was a blank page. But all nobodies were at first(besides Xemnas). They had no memories of their old self, that happened while their hearts grew back.
Now with Roxas it's more complicated than that, he had to remember Sora's life, then Ansem erased his memories etc... We can't know if he was eventually gonna remember Ven's life.
What I meant is, since I REALLY doubt Vanitas is ever gonna fuse with Ven, maybe using Roxas to heal Ven and fuse them can bring Ven back, with Roxas' memories. I don't think there would be any conflict, they might be (or not, it's just a theory) the same person only they went through different experiences. They would be the same. Just like Lea retained all of Axel's memories.
Ouch, from where did you get this stuff? Roxas does NOT have Ven's body. Ven's body is sleeping inside the Chamber of Waking for over 10 years now.
Roxas has
Sora's body and soul because he is/was Sora's nobody. Roxas is more from Sora than from Ven because Roxas was born from
Sora's heart falling to darkness and he was using
Sora's body and soul.
The only thing from Ven was that he carried Ven's broken heart, which made Sora's body look like Ventus, hence Roxas looking like Ventus.
Wrong, Roxas was the
only Nobody that was in a blank page at first. He had to develop completely from nothing. This and that he co-existed with Sora is what makes him so special.
Naminé and Xion also had no memories, but these aren't really Nobodies.
All other human-shaped Nobodies always had the memories from their original selves.
Roxas only "remembered" bits of Sora's life because Naminé messing around with Sora's memories caused some to flow into him, he never associated these memories with himself.
They aren't the same person, that has already been confirmed. Roxas and Ven aren't the same so there would be no benefit from fusing them.
Roxas can't be counted in the same vein as Axel/Lea because of his special status. They can't be compared, especially not with Ventus who never had a Nobody.
I'm begining to think of hearts as more of a gooey amorphous substance that can be linked, and divided by memories. So, Normal nobodies like Lea which don't loose memories upon loosing their heart can develop a heart then gain their old heart while still having one heart because they have one person's memories.
While a freak like Sora has many sets of memories that divide his gooey emotional stuff into several hearts.
A person's heart has no form without memories to shape.
Well, Nomura did once say that hearts do not really have a definitve, tangible form, so that may play in here.
Axel not becoming "different" that Lea would be explainable with the old memories being used as a base, so the sense of self created is then astoundingly similar if not the same, yet with persons who have more than one heart in play or co-exist with their Nobody the Nobody develops differently and diverges from the original self (and therefore also the new heart of that Nobody).
That last sentence makes much sense, as the main form (let's call it the core) would be the bud, the unrefined base of a heart. Only by creating memories and a true sense of self and identity a true heart is formed.
This "forming" of a heart was also hinted by Nomura describing Ventus' state after his heart was heavily injured the first time and when he was brought to Eraqus:
BBS Ultimania said:
-- Ventus awakens with Sora's help, but at first his eyes are blank, and when he first meets Terra and Aqua he falls asleep under their barrage of questions.
Nomura: At that time, although Ventus has awakened, his heart is not fully formed.
Coincidence? I would think not.
As Ventus began to recover over the four years between this scene and the actual BBS-game under Terra's, Aqua's and Eraqus' care I would say that was when his heart grew and became more stable again, also in big part due to him forming new memories that helped forming his wounded heart back.