[More than ever, Roxas wishes Terra had explained at least some of what had happened to Aqua. He'd do anything to help his friends, but anything shouldn't include making this kind of decision about how much to tell her now.]

He used to call himself Ansem. I wasn't around back then, but when he lost his heart, he changed it. That's kind of how it goes for people like us. Ansem to Xemnas...Sora to Roxas.

But he wasn't even the real Ansem. I never met the real one, but they said he was betrayed by the original members of the Organization. And their leader stole his name so no one would find out. I guess he makes a habit of taking things that are important.