[ The idea of losing your heart, of losing who you are, is a disturbing one. That's what leads to the creation of Heartless and Nobodies, after all. It's not something anyone should have to experience. Sora wishes that he'd been able to prevent it somehow. ]

There are a few different ways. [ It's not a pleasant topic, and Sora glances across the aisle as he explains. ] If your heart gets corrupted by darkness, or if it's unlocked by a Keyblade. But... [ He looks back to Cain. ] Do you remember what happened, before you lost yours?

[ Sora never got a proper explanation. There hadn't been time for that when they'd been rushing to recover everyone. But he's hoping that Cain will be honest with him now. ]