That's not his power though. That's the Void's power. Kefka could probably do the same thing and more using the statues as well. He used the Void's power to make the cities disappear, but he didn't gain the Void's power until he became NeoX-Death, just like Kefka used the statues' power to kill Gestahl, but didn't gain their powers until the end of the game, where he drained the power of the statues.
Well, it was said that the statues were the source of all magic in FFVI. Though it didn't say the universe, it did say "all magic" and the magic of the world and the magic of the universe do fit under "all magic" right?I really doubt that Kefka have control over all magic in the universe.