aftewr you get your national pokedex you will get a place where you can catch it only of you have the bayleaf on Ruby.
You can't catch Arceus. You can only catch Arceus in Pokemon Platinum.
Trade over the GTS as there are no more events for it
Pokemon to be exact dimond and pearl version on a ds
get the azure flute then go to mt.cornet when you are there use it then special steps will appear go up them and soon you will get arceus. hope this helps
Dialga
You can't catch arceus in pokemon white.
arceus if you can get one other than that i would say giritina
i know you can catch a ditto
You cannot catch Arceus in Black or White. Arceus was an Event-only Pokemon from the 4th generation and must be transferred over.
luck
run after it !!
no you cannot catch arceus in pokemon black without action replay