[She starts to answer, then stops, frowning at herself.] That's right... I don't know how I forgot. Lightning never took those books back. I can bring them over later.

...About the worlds. Lightning and Hope are from a world called Cocoon, but they were branded by a fal'Cie from Pulse. The worlds have similarities between their fal'Cie, but there are little differences too, and sometimes the books talk about both... there was a war between them. So the Brand they were given is a Pulse one. It came from the fal'Cie Anima.