Ok so when Sora meets Roxas in the dream or whatever Roxas said this couldve been the other way around, but it really has to be you, what did he mean by that? Did he mean that Sora had to be the 13th vessal for Xehanort or did he mean that Sora is the one who has to take the hurt from Roxas or whatever, or did he mean something else? thats what really confuses me.

I honestly don't know... I guess that is too important... but I think he meant about Sora to undo the hurt of him and the others. Why would Roxas tell Sora to be a vessel for the bad guys? o.o

I'm pretty sure he meant the 'being the 13th vessel' thing...I think. Or maybe the 'save everyone from their torment' thing...but then again, how would he know about all that? And I'm still wondering how he knew what Axel said to Xion...when they were CLEARLY alone. Roxas makes no sense... >____>

No, I think he meant that Roxas could have survived and been a real person on his own, but it was Sora that had to wake up in the end.

He was saying that Sora could've stayed asleep and Roxas would have been his own person, but Sora had to wake up in order to stop Xemnas and then help everyone.

Basically:

Roxas awake while Sora asleep

vs

Roxas "asleep" while Sora awake

he's telling Sora that he is the one that will undo the hurt of all of those connected to his heart.

so far Lea is already off the list of hurt (I think).

Now Sora needs to undo the hurt of Terra, Ventus, Aqua, Roxas, Namine, and Xion. and that will be taken care of in KH3.