What if the reason why Vanitas is back is because Xehanort is trying to harbor hearts in the dream world (part of his many roads he would take) just like Sora, except Xehanort is in a sense stealing the hearts of others to give him more power? Just a thought, BTW hello everyone! I'm new here but i've been following the site for a while now! As for terra coming back...I don't know lol