Re: Simple Questions Simple Answers (XY Edition)
You can get more mega stones. After you participate in the Battle Maison once go to the northmost part of Kiloude and go from there. After you do that, going to Lumiose will initiate a post-game sidequest, with an old friend, and of course you can catch some legendaries. As for training, the restaurants in Lumiose are good places to train. They cost money, but if you do the battles correctly you'll make a profit. Personally I like battling hordes in victory road (they give more experience than regular wild battles.) Unfortunately you cannot rematch trainers as far as I know. I really wish they would bring back the vs. seeker, but for someone reason they won't.
You can get more mega stones. After you participate in the Battle Maison once go to the northmost part of Kiloude and go from there. After you do that, going to Lumiose will initiate a post-game sidequest, with an old friend, and of course you can catch some legendaries. As for training, the restaurants in Lumiose are good places to train. They cost money, but if you do the battles correctly you'll make a profit. Personally I like battling hordes in victory road (they give more experience than regular wild battles.) Unfortunately you cannot rematch trainers as far as I know. I really wish they would bring back the vs. seeker, but for someone reason they won't.