Whenever time travel pops up in a story, it causes problems. How is it possible? Why is it necessary? How did it not completely skew everything else that happened?
It’s not an altogether unexpected development in KH, since the plot gradually becomes more complicated as the games progress anyway, but it still raises some questions.
Xehanort isn’t the only one who turned into a Heartless, so can others who have been Heartless at one point or another travel through time as well? If so, does that mean Nobodies can travel back to before they had their hearts removed and interact with their hosts?
Perhaps it has some bearing on why we’re seeing dead Nobodies like Marluxia return in KH3. But even more importantly, it might relate to Terra’s redemption. He’s not exactly Heartless, but he’s fused with Xehanort’s heart, and he would still have a version of himself in the past.
It would make sense.
Typically, villains have some part of their grand schemes come back to bite them, but that hasn’t happened yet for Xehanort; he’s long overdue for some delicious irony.