Originally Posted by Judge Dredd
did you get to battle all the gym leaders from the other regions?
You only do that in the Pokemon World Tournament. I did the PWT one time, but only the intro versionyou go to when you first enter into Driftveil City.
Also, note, there is one former gym leader that does not appear in the Pokemon World Tournament. Koga does not appear. Guessing it's because he was upgraded to the Elite Four in G/S/C/HG/SS.