Where to find Gengar
LocationMorn.DayNightOld Chateau (Room with Painting)4%4%4% at Level(s): 16GBA Slot: RubyOld Chateau (Room with Painting)4%4%4% at Level(s): 16GBA Slot: SapphireOld Chateau (Room with Painting)4%4%4% at Level(s): 16GBA Slot: EmeraldOld Chateau (Room with Painting)4%4%4% at Level(s): 16GBA Slot: FireRedOld Chateau (Room with Painting)4%4%4% at Level(s): 16GBA Slot: LeafGreen
The Pokémon that appear in Diamond when Emerald is inserted are Pineco, Gligar, Shuckle and Teddiursa/Ursaring. Haunter and Gengar are also included in the game but Haunter and Gengar are added regardless of the Gameboy Advanced game as long as there's 1 inserted.
you can find them underground if u look long enough
A Pokemon adventure on Pokemon Diamond Verison can last forever if you wanted it to.
as long as you want
I think you find it in fuego ironworks near floaroma town (you will need to have a Pokemon that knows surf) use poke-radar and do long chain until you find a magnemite.
There was a Pokemon event at Toys R Us a long time ago that allowed you to obtain it, but it's no longer available now.
You can find dialga in the pillar, but I don't know where the pillar is because it was a long time ago when i got dialga.
If you mine underground long enough, you will find them, but they are very small, so you have to look everywhere, you can also find them on wild Luvdisc
To catch every Pokemon, you need action replay for the few last diamond legendaries. You will need Pokemon fire red/leaf green and emerald. Migrate them to Pokemon diamond. In Pokemon diamond, fill up your pokedex by catching Pokemon normally or with poke radar, or use gts. It will take a long time to catch all Pokemon
the really long grass in resort area no pokeraider
you have to go underground and dig until you find a fossil, you can also find Aerodactyl, bastiodon, ammonite, and omastar. This takes a long time to find a fossil though.
i used marriland to find this out but in the long run honchcrow has higher maximum stats but if it is speed you want you need staraptor