FFXIII-2 Change the Future trailer

Yet another trailer for FFXIII-2, looks like Lightning has pulled a Peter Bishop! And only Serah seems to remember her sister's existence!
From the trailer it appears Serah will be a playable character in XIII-2 as she tripping the time fantastic with a new character Noel....who looks a bit like Sora from Kingdom Hearts. The trailer also gives us a better look at the primary antagonist Caius...get it? Chaos. :/