That I don't really have much of an answer to. Perhaps it was due to the different changes...

[He pauses, considering how to word this.]

The world Tifa and I first met in was a world that had used powerful magic that almost destroyed itself and other worlds along with it. They were able to stop it by freezing time, including those other worlds, and through the use of bond animals were able to pull individuals from those worlds to try and reproduce enough magic to restore it and fix the problem.

[WELL JOSHUA WANTED A STORY HERE IT GOES.]