Birth by Sleep Up to date theories

Hey guys, it's been a while since I've seen some old theories being revived or renewed.
I wanted to get some feedback about any theory you want to talk about.

1. Terra - Xehanort (Same: i think so)
2. Ven - Roxas (Ven is Roxas but Roxas isn't Ven)(soul theory)
3. Any other ones those are the main ones I'm interested in.

 

Explain that right now then.

 

I remember this theory now.
I remember saying it might be possible, but I didn't really agree with it.
A reverse Nobodification just doesn't sound right.

 

How does he lose his heart? The heartless didn't exist until the year after BBS. And even if the process was possible without the heartless what became of Ven's heart?

So a 5 year old's heart enters a teenagers body and looks like the kid's heart? Doesn't add up. Plus the process of a nobdy just coming in contact with a newly freed heart doesn't allow a whole being to return. In KH2 when Ansem the Wise blew a hole in Xemna's Kingdom Hearts hearts rain down on dusk nobodies. They try and grab then, but no luck. And if that was all that was needed to be whole again surely the nobodies of Organization 13 would have tried at it.

Would it all be history? Ven's heart and Sora's body aren't accounted for. Did Sora's body and soul create a nobody of their own? If so why didn't they have to return to Sora so he would awaken? The memories they had would be needed for his return. Plus why doesn't Roxas have Ven's memories?