If you want your pokemon to gain levels quicker, go to battle, then click on the option to battle a computer controlled trainer. Make sure you have a ghastly (Or any other ghost type pokemon) with you. Type in zedjapoison. The trainer will have 6 level 100 pokemon, but they only know the move splash. Try to get all your pokemon with you to battle and after you do that keep attacking the trainer's pokemon with your ghost type pokemon until you win the battle. You should get a lot of money and the pokemon with you will gain a lot of experience points. There is also zedjafire, zedjaice, zedjabug, zedjapsychic, and more. I hope this helped!