There was an event that if you transfer an arceus to your pokemon heart gold or soulsilver version you will be able to get dialga palkia or girantina.
but I got an arceus and I went there as it said but nothing happened.
so I was wondering does it need to be a event arceus?
Beacause it's not
It must be the special event arceus from an event that has already passed so sorry:(
No! You can do this event twice - both with Azure Flute Arceus and giveaway Arceus! Great, you can get 2 of 3 dragons! Nice, isn't?
BTW, if you traded that Arceus, it may be hacked
You can only get them with the special event arceus.
To get Dialga, Palkia, and giratina bring the arceus you get in a special event to ruins of alph in the johto region.