Well I have been recently playing Kingdom Hearts 2 final mix and I have noticed that in some areas there are orbs wich lead you to battles with members that were in Chain of memories ,but they are dead so how are they in Kingdom Hearts 2, can somebody please exlpain.

i think there data from something and thats why when they appear theres numbers around them heres an example http://www.youtube.com/watch?v=FAHSahu7SJw

They are called "Absent Silhouettes", which are basically the remaining thoughts and whatnot from the members that were killed. Finding a picture of their weapons will reawaken a silhouette of them. There are also 'Data' versions of them, which are data stored of their fighting tactics, powers, etc, and they are far more powerful than the AS versions.

they are called absent shilouetes, they are just data battles, therefore, there is no story line about the dead member's data other then the fact about fighting them

They're "absent silhouettes" (I probably spelled that SO wrong! ). I guess they're kinda like the Lingering Sentiment?

I like fighting them, cause it's better than fighting with the cards!