[quote=@RyuShura]
I was just going to be from one of the existing worlds, like Hollow Bastion or one of the main connecting worlds. 
[/quote]

Fair enough, but Hollow Bastion's been lost since even before the events of KH1. It was the first world to be swallowed/overrun by Heartless after all. So you'll still need to have been [i]somewhere[/i] at the time the Empire started attacking.