if you mean lugia you get the silver wing after beating the goldenrod takeover and beat Clair to battle the kimono sisters then you get the tidal bell
you find a secret place you find a legenary pokemon that holds this stone defeat it you get it.
if it needs a avent yes but if its like mispreyit probly not
no you can trade soulsilver pokemon to black
he is not in Pokemon soulsilver or Pokemon heartgold
Rayquaza, latios, Groudon, regice, registeel, regirock and one other sorry i dont know the name...
POKEMON SOULSILVER come with a poke walker and the Soulsilver game
Pokemon soulsilver and Pokemon heartgold are basically the same game just different versions but i do recommend buying Pokemon soulsilver
SOulsilver
yes you can catch all the legendaries you dont have to pick one you can get all of them
You CANNOT LEGALLY download Pokemon Soulsilver.
You can't catch bastiodon in Pokemon soulsilver.
You'll need to trade for it from Pokemon HeartGold. It is not avilable in the wild in Pokemon SoulSilver.