You’ll need to have gotten Deoxys in Emerald but the Deoxys is found on Birth Island which requires an Aurora Ticket to reach him, and sadly the event for an Aurora Ticket has passed so it’s no longer possible to get Deoxys in Emerald (unless by some crazy stroke of luck you find someone willing to trade theirs). If you do have Deoxys on Emerald, you can migrate him to SoulSilver, otherwise, you can’t get him. If you don’t have a Deoxys on Emerald or don’t want to migrate, your only other option is to find someone in the world who has a copy of a compatible game (such as another copy of SoulSilver or HeartGold) with Deoxys on it, and ask them to trade with you. I’m not sure if it would work anymore, though, because the wifi club is permanently down for the DS. It may still work for the 3DS and the 3DS is the only other gaming console able to play DS games.
If you have Pokemon Emerald you can transfer it from there, though you may need an item to get him from there, I can't remember.
No Pokemon game has cheats sorry.
no
cheats
You need the event to find celebi without cheating.
train in wild Pokemon battles through out the game
There is no possible way without hacking or cheating. I heard they are bringing Mew back in Pokemon Heart Gold and Soul Silver.
not for emerald but for Pokemon silver for Gba
You can't, you must trade from Emerald (which had an event to get to Mew), or trade from Pokemon Ranch (if you unlocked it).
you can get arceus cheats
Go to www.cheats.it
you don't
Do you need a cheat for Pokemon crystal? cuz I have thoze.