Is this right????

this question has been on my mind ever since kh1
if riku gave himself into the darkness and was able to control it, but sora couldn't avoid being transformed into a heartless. Then how is possible that sora was still the holder of the keyblade?????????

I have no idea... but perhaps it could be because Sora's heart was saved by Kairi and Rikku's wasn't.

could be. Other question is if light and darkness need each other to exist, and if sephirot is the dark side of cloud What would happend if 1 day on the eternal fight of this two characters 1 losses??? would the other 1 dissapear as well???

In concern to Sephiroth and Cloud, taking into consideration also the information given in Advent Children, I would say that the only way for Sephiroth to be destroyed is if Cloud stops living in the past. That means he has to let go off the guilt he feels about Aeris' and Zack's deaths and move on (meaning take care of Tifa, who, as she herself mentions in KH2, has (contrary to Aeris) light).

Although, mind you, I don't think Sephiroth will ever be destroyed in the FF world because the fans would make quite a riot if Cloud beats him.

seems like a very interesting subject, but still that didn't answer my question. Would any1 dissapear after 1 is beaten???
better yet, what happend with this 2 characters on the kh2 after the battle???they just dissapear didn't they???

Yes they did, I bet they went off to another world. Earth in Advent Children. But a huge chunk of the Sephiroth-Cloud battles is missing, their battle in KH Final Mix. This seems simple enough right? Go to Amazon, eBay or someplace like that, order Final mix and beat right? WRONG! KHFM, only works in the Japanese and Asian Versons of the PS2, so we need someone from Japan or another part of Aisa to tell us what happened, that or learn Japanese.

so we need to find some asian people and ask them but how?
any ideas????

Still, I don't think that battle will ever be over. I mean Cloud has beaten Sephiroth two times and still he manages to come back (which is good because Sephiroth is too good to be death... I mean he is the ONLY character who has his own song!).