Go to the spear pillar and stand on the Flute stone when you enter then use it there will be stairs go up them and your destiny awaits
If they where traded to you the game is not glitch'd
im pretty sure you can't catch it without cheats, its liek shaymin or acreus
You can't.
action replay
Hey To get to it you don't. But to get Arceus ypu need a special flute (forgotten name). However, acreus is only obtainable in events.
The strongest wild is heatran Lv.70,Garatina Lv.70,Regigagis Lv.70,and the strongest Acreus the god of all Pokemon at Lv.80.These are the strongest Wilds but they are all ledgendaries.
Pokemon diamond
the only way (i think) is by cheating to get the azure flute. But if you have it go to the top of spear pillar and go up the stairs. As of now only an a cheat that gets you a flute. You go to Spear Piller and play the flute. Then a Staircase apears and at the top is a wild Acreus. A battle starts and you can catch the legendary pokemon.
Pokemon diamond Pokemon diamond Pokemon diamond
you cant be a Pokemon in Pokemon diamond
It apparently created the universe, but some believe Ho-Oh created acreus.
No even if a code did exist you wouldn't be able to find acreus so no.