*Make sure that you have at least 2 or 3 legendary pokemon*

First, go to the Battle Frontier. Once you arrive, go straight to the Battle Pike and enter. Once you get in, just talk the lady next to the statues. then talk to the Lady on the red carpet. Press enter and then press open level or Lv. 50, she will say that you cannot enter because you have all of the legendary pokemon with you. then, get out of the Battle Pike. Go to anywhere where you can find wild pokemon. Just go into the tall, after a few tries, you will EVENTUALLY find a shiny pokemon! THIS TRICK WILL NOT WORK 100% OF THE TIME!!!