you first have do a hearthome contest and win then she comes back
The 6th Gym Leader on diamond in Byron. Bryon has Steel Pokemon and is located in Canalave City. Canalave City is to the west of Jubilife City.
The 7th leader is Candice in Snowpoint City
The Second Leader Is In Eterna City
hearthome city leader
theres a house in pastoria city he will get the move back he will want a heart scale which u can find underground
For Diamond and Pearl Fantina has: Drifblim Gengar Mismagius For Platinum she has: Duskull Haunter Mismagius
In sunyshore city
veilstone city
Go to Contest Hall and talk to this girl with purple hair and purple dress. She is the Gym Leader, Fantina, who has ghost types.
The 6 gym leader in at Canalave City. the gym after the hearthome City gym!!!!!
I think you have to go back to Hearthome city. There you can enter the gym and fight Fantina.
she's at the contest hall (the big brown dome in the back of hearthome city)