How do you catch Arceus?

You have to use cheats you get a azure flute and travel up to mt coronet and blow the flute, you go up the stairs and you get an arceus! but if you use the cheat for that you may want the 100% pokeball cheat or the master ball cheat

cheat and get azure flute then go to mount cornet summit and blow the flute

go to a download or a event at gamestop or at a wifi hotspot

The only way to catch Arceus is to hack an Azure Flute in Diamond, Pearl, or Platinum and go to the top of Mt. Coronet.