by trading it from Pokemon xd
You cannot. Dark Lugia is only available in Pokemon Colloseum.
it wont with celibi but it might work with lugia or dark lugia could be a shiny lugia.
No.
You had to get it at a special event a couple of months/years ago. You may be able to hook up Pokemon Emerald with a Gamecube and trade a purified Lugia to Emerald.
You can't get Dark Lugia in Pokemon Silver, Gold, or Crystal. You can get Dark Lugia in Pokemon XD though. For Pokemon Silver, Gold, and Crystal it is just the regular Lugia.
Dark/Shadow Lugia is only available in the Gamecube game Pokemon XD: Gale of Darkness.
Can't
Yes, if you get the Rainbow Wing, Oh-oh is in the same cave as Lugia.
Dark Lugia is also known as Shadow Lugia. You can get it in the game Pokemon XD and it is possible to trade it over to Diamond version.
Sorry mate. No such thing as dark lugia
there is no way srry <(-_-)>
you need an AR.