Okay so I don't really spend much time on the forums so I don't know if someone posted this answer already. I just want to know how a heartless and a nobody exist at the same time. Ansem was alive during the time when Xemnas was alive. In re:chain of memories, Ansem was shown as Diz in disguise facing Riku while the real Xehanort was inside Riku. I know that Xemnas is alive because the organization is still there and the talk about their Superior. However, if they can exist at the same time then how come Sora and Roxas can't. I mean Kairi and Namine held hands and existed. Why do they have to live as one. Does it make Sora stronger or something. I kinda felt bad for Roxas when he had to fuse with Sora and leave his life. I don't remember if you need to have them as one because while Sora was sleeping Roxas was around, but when Kairi was on the island Namine was in the castle. So they can live seperate lives and be fine. So why do they have to fuse and the nobodies have to leave their lives even though it is fake it still kinda sucks.