Arceus is in the hall of origins directly above spear pillar you will need the azelf Flute(event item) to make the stair case appear that leads to arceus(not easy to get)
You had to get Arceus in an event. The event already ended so maybe you can get some codes.(I don't know any codes) Or you can trade with someone else who has Arceus. Then you can get to The Ruins of Alph and get Palkia, Dialga, or Girantina with Adament orb. Then you can trade back(unless you're keeping it)
you have to have an arceus
Arceus has never been distributed as an egg. If you are referring to the egg from the HeartGold/SoulSilver Arceus event, it hatches automatically.
You cannot find Arceus in Pokémon SoulSilver, the only possible ways in order to get Arceus in "SoulSilver" is via a Nintendo event, via a cheating device or by trading with someone who has gotten one.
EVENT!
You can only get Arceus from Pokemon D/P/Pt.
To get an Arceus in Soulsilver or Heartgold, you needed to download it at an event, otherwise you would have to use codes or trade from another game.
Through cheats
get an arceus of platinum and trade to soulsilver then go to the ruins.
You cannot catch Arceus in Pokemon Soulsilver nor Heartgold, You must either transfer a Arceus from D/P/Ptt or Receive one through the Arceus Event.
Yes you can get Arceus if you have a Pokemon platinum,diamond,or pearl and you have giratina dialga and palkia trade them to your Soulsilver and then a mountain will appear somewhere and then Arceus will be in there
It must be the "12 Movie Event Arceus"
I'm guessing, you CAN'T