You have to ethier, choise one- Trade it with some one else choise two- Trade your haunter with a friend ( trade it back) choise three- I think possibly that you can get one from the old chatu but I'm not for sure.
Sorry to say, but Gengar is not obtainable in the wild.
you trade him. and he will evolve into gengar. you trade him. and he will evolve into gengar.
no
Get a Haunter and trade it with a friend in the Union Room, then it will evolve into Gengar if it doesn't have an everstone.
yes except gengar he can faint if a foe has a empoleon
You can use the Pokemon modifier for action replay but I don't know the code right now.
Yes at the Hearthome gym leader's trainers.
Drifblim (Lv. 32), Gengar (Lv. 34) and Mismagius (Lv. 36).
A good team for Pokemon diamond or pearl is probably Empoleon, Staraptor, Roserade or, Steelix, Machamp, and Haunter or Gengar.
Haunter evolves into Gengar by trading. Since the GTS is not functional in Pokemon Diamond and Pearl anymore, you will need to ask a friend, who has a copy, to do a trade-back with your Haunter.
Gahstly will evolve at lvl25 to Haunter then trade haunter to evolve to a Gengar.
To get a Gengar, you must trade a Haunter and it will then evolve into a Gengar.