If you're not using AR then you have to Migrate Ho-Oh from GBA games. When they migrate, you will have to go to the Pal Park in diamond to catch all your migrated Pokemon. You can transfer up to 6 Pokemon a day
Action replay
No
no you have to get is from an action replay or go to a Pokemon event
you trade it or use action replay
U HAVE TO MIGRATE OR ACTION REPLAY
Not Possable
It is Impossible without an action replay
You can't without an action replay.
Missingno is not avalible in Pokemon Diamond without help of the Action Replay.
You can't get the Azure Flute without the Action Replay or event.
No you cannot.
put me in Pokemon