I don't know how. But when I asked Occidi how I could get everyone back to their worlds and put things back to how they should be, she said it isn't possible as we are now. We're not free to leave... because we're not 'whole'.

[Whatever that means. It's vague, but it's a better answer than nothing. And now Terra knows what he has to do.]

Roxas, I have to keep fighting CERES. Whatever happens, I want to free everyone so they can go back to their homes.