I remember having to defeat Xion. She becam a mecganical version of sora or somthing... I wish Roxas would have mentioned her in KH II or something. although 358/2 days came aftern KH II...
not only did she die in KH358/2, she was "born" in it as well, and I'm both a zelda/Kingdom hearts fan, and was sad to witnise. DON'T WORRY THOUGH (spoilers) SHE DOES MAKE some APPEARENCE IN KH3D!
she didn't die.. she went back to sora's memories..then she will gone forever. Same with Roxas. bec They had Sora's memories.. If they won't back to Sora.. never able wake up..