Ok. So before anything, get 2 Blue gummies in Craggy Coast. You don't want to waste time
searching for in. After finishing the Blizzard Island and Crevice Cave Mission, Corphish
will be standing in the middle of the crossroad. Talk to him and he will tell you to go
talk to Sunflora on the Basement floor 2 of the guild about a place called Surrounded Sea.
Go talk to her so you can go there. Bring at least 5 reviver seeds if you are a fire or
rock type. At the end (20th floor I think) is 2 chests and a wonder egg. GET THE EGG TO
ADVANCE. The next mourning it will hatch into Manaphy. You automaticly go to Chatot about
what the pokemon is. Then it cries for food (this is what the gummies are for). Go get one
and feed it to Manaphy. Then it will sleep with you. Manaphy will ask for another gummi.
Go get it. Then you go to the beach with Manaphy. The next day it will be sick so go to
Miracle Sea (you will get that then), reach the 20th floor and beat Gyaradoes (bring an
electric type for this) to get Phione Dew. This cures Manaphy. Next day Manaphy has to
leave to the sea with Walrein. After defeating Darkrai after a while, Creasilla asks you
to join your team. In a few days Manaphy comes back a little older and asks you to join
the team. In a few days it will come back after you wake up and tell you about Marine
Resort. Have fun with level 40 Manaphy.