If I'm correct, the Gracidea flower cannot be obtained in Pokemon Diamond. Sorry! (Note: The Gracidea can be obtained in Pokemon Platinum.)
From Great Marsh after you have obtained National Pokédex.
no
Once HM02 is obtained from Veilstone City
TM24 (Thunderbolt) can be obtained at the Game Corner in Veilstone City, for 10000 coins.
Piplup is obtained as a starter in Diamond and Pearl or through trades.
If I'm correct, the Gracidea flower cannot be obtained in Pokemon Diamond. Sorry! (Note: The Gracidea can be obtained in Pokemon Platinum.)
Action replay is not an Pokémon item that can be obtained in Diamond.
trade it from soulsilver
From Great Marsh after you have obtained National Pokédex.
Sorry, but Entei can not be obtained in Pokemon Diamond and Pearl itself, you must transfer it from old GBA games and use the Pal park in DP to catch him.
Cyndaquil can only be obtained by migrating it, or by cheating or hacking.
You have to migrate from Sapphire or Emrald.
Put Honey on a tree
no
There is no such Pokemon as Mewthree it is a hacked Pokemon, so consequently it cannot be obtained in Pokemon Diamond.
us a dusk stone but misdreavus can only obtained in pearl while murkrow can be obtained in diamond