It is possible to get Arceus in Pokemon diamond?

Answer 1

The only way to do so is to cheat with action replay or get an azure Flute from mystery gift. The event has already passed so the only way to get Arceus is by cheating. The following cheat is the wild Pokemon modifier code. This is the code:

94000130 FDFF0000

B21C4D28 00000000

B0000004 00000000

94000130 FEFF0000

00000890 01ED0001

D0000000 00000000

DA000000 00000892

DC000000 00024620

C0000000 0000000B

D7000000 00000000

DC000000 00000006

D2000000 00000000

To activate: Press (L+R) on inventory screen. Master balls replace your first item.

This code allows you to get any Pokemon possible from Generations 1-4. The cheat will give you 493 master balls. If you wanted an Arceus, you would take the Pokemon's pokedex number, which is 493, and then subtract 493 and 493 for the master balls in your bag. The answer is zero. Thus, you will throw zero master balls away so that you have your pokemon's pokedex entry number. Holding L, walk into the grass or cave and an Arceus will appear. DO NOT PRESS B! The code will not work if you do this.