Youve just missed the darkrai event and cresselia isn't an event, you just go to full moon island. :)
you find cresselia on full moon island
Darkrai is a dark type of Pokemon. You can catch one in Pokemon Diamond version on Newmoon Island but you need a membership card.
no you do not
NO
You dont catch Darkrai in Pokemon Pearl. You can catch it in Pokemon Platinum at level 40.
You have to trade from diamond or pearl
I think you get it from shadows of almia
Girantina, Heatran, Dialga, Mespirit, Azelf, Uxie, Shaymin, Cresselia and probably Darkrai.
After you catch cresselia go back to Fullmoon island. You can then catch darkrai if you have action replay. Pick the cheat code that makes you walk or run anywhere. Then go right at Fullmoon island until you reach Newmoon island. Go in the cave and you see darkrai.
well after you rescue him on her nightmares by darkrai use the pokemap or something like that and then catch cresselia but be care full use the pokemon that knows -block-or-meanlook-for the pokemon cant get away hope i helped
you could catch Pokemon from other regions including rotom,heatran,regigigas,giratina,cresselia,phione,manaphy,darkrai,shaymin,and arceus.
You have to get the National Dex, then go to Full Moon Island.