you get a dark Pokemon for example mightyena
You have to beat the gym leader first... then you'll find them there.
You need Ghost-type pokemon, Dark-type, or maybe Bug-type pokemon. Don't use Fighting-type pokemon.
Go to Mossdeep city and beat the gym.
dark
You get it after you beat the gym the go to steven’s house and dive is on the table
you beat a cave and use dive in mossdeep city thats all!
After you beat leader Norman
get better pokemon
Beat the gym leader
get a pokemon, then you train it, get it really strong, and beat th ecrap out of all the 7th leader's pokemon. Its easy.
after you beat the mossdeep gym you have to go to the space centre and fight team magma with steven. after you beat them, you go to Stevens house in mossdeep city and he will give you TM 7, dive
with fighting type pokemon