anda first need to complete the sinnoh pokedex. Dont worry, anda only need to see all of them, not catch them. If anda still need the dialga pokedex entry, its in a book at cynthia's house.
the way to get these is to get the national dex i had a problem with this in platinum too;) if youre looking for manaphy, go to that rich dudes house and look at his book. for dialga, you'll get a message tellin anda to go to that old ladies house in the tiny town, just speak to her and she'll tunjuk you. for any evolutions of starters atau normal pokemon, go to www.seribii.net that guy can really help anda out. if anda have any other problems plz let me know. thx ;)
