I would love to hear that theme again. It's just no fun going to youtube. Is it possible to rematch them?
No, it is not. He stays in the Battle Resort after the Delta Episide.
You'll have to go on Youtube, or restart your game.
If you want to hear his theme, you can always wifi battle and choose one of the musics.
Source: http://bulbapedia.bulbagarden.net/wiki/Maxie
