"That's... something of a blessing for your world in general, then, though one that has extremely horrifying implications for your ancestors. I can only hope that madness is dispelled by death."

Having seen plenty of souls linger after death back home and knowing that such powerful forces exist in Sion's, he can only assume that those dead don't simply disappear. Yet if they must endure such suffering even then, perhaps non-existence would be a kinder fate.

"So it's not merely the destruction of the world that he seeks, but also its... perversion, in a way? It must be molded to suit his purpose before he rids himself of it?"

That sounds more like the Emperor than Kefka, and not in a manner that he likes.