You mean Fantina? If so, go to Canalave city. The gym leader there uses steel Pokemon. Hope I helped.
In platinum after Fantina, who is third leader, go to veilstone city and beat Maylene. She uses Fight-type pokemon.
it would be best to use ghost Pokemon against the gym leader
If you want to see an old man with a ghost Pokemon because you need to see a ghost Pokemon for your pokedex, well, there's a gym leader with 3. If you need to see this PARTICULAR GUY, then (wait, first I don't know why because I've beaten Platinum without finding an old guy with a ghost Pokemon, but) go back to the places you've been and explore everywhere. The world is a big place. It might take some time.
i only know fanita and she's the third gym leader (ghost type)
Luxio it learns bite and dark type moves are super effective on ghost types
Fantina is a Ghost type gym leader, meaning normal and fighting types won't have any effect.
He is the fifth gym leader. After you have beaten flannery, the 4th gym leader, you can fight him. THEN follow wat's below... have a ghost type or fighting type like sableye or combusken or makuhita. make sure ur ghost Pokemon has an attack that may hit the foe becus ghost attacks don't work against normal Pokemon
You can get a badge and TM Shadow Claw after beating the third available gym leader, which is Fantina with the Relic Badge. (She uses Ghost types)
Giratina Type: Ghost/Dragon
You have to beat the Hearthome gym leader then you can get through. (do NOT use normal type moves on her because she has ghost type poke'mon and normal type moves won't effect ghost type pokemon).
enterna
A ghost!!!!!!!!!!!!!!!!!!! ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Gengar is a powerful ghost type of Pokemon. In Pokemon Platinum it is possible to capture one by going to the Old Chateau.