You need a special Pokemon event.
SORRY,but you can't catch DARKRI in pokemon soulsilver. but u can trade it from pokemon diamond,pearl,platinum.
The boy in Pokemon diamond and pearl have nightmares when darkri shoot a nightmare ball at the boy when he is in the garden and some of the Pokemon attacted darkri and darkri said"leave now".
No
You don't unless you import from a Pokemon diamond, pearl, or platinum game after you have unlocked the ability to do so.
Dialga,Palkia,Giritina, Darkri, and i think Cressilia....... im not too sure about Palkia, that might only be in Pokemon pearl you can catch palkia
go to pokemon.com and they tell you the events what about after allevents are over
trade from diomad/pearl/platinum or cheat
arcres shaymin darkri dialga palka uxie
u hav 2 get the members card or download it on 2 ur game 4rom toyrus or just buy a cheat system
to find out, you coud get on youtube.com and look "Darkrai in Pokemon pearl" or get on a website called www.chaptercheats.com.
Not in the real world but it is available to catch in a couple of the pokemon games.
You can't. It is only obtainable by event in Diamond, Pearl or Platinum