You get it by doing lots of missions. Then, you get it from a Elekid.
he is in amp pains if you have a secret slab and a mystery part
concealed ruins with secret slab or mystery part
Go on the internet and get wonder mail.
zapdos is in amp plains on 7F but you need a mystery part or a secret slab
look it up on google ("pokemon explorers of darkness secret slab") and enter it on the main menu
You must have a Secret Slab/Mystery Part. He is in Dark Crater, 10F.
It is in Final Maze 40F you need secret stone plate or enigma part in bag (secret slab or mystery part)
You can find it in Surrounding Sea floor 18 with the Secret Slab or Mystery Part in your treasure.
Yes, you can find Celebi in mystifying forest if you have the secret slab and go to the 10th floor.
get either the mystery part or secret slab, then take one of them with you to Concealed Ruins (I think). Raikou will appear on the 20th floor.
http://www.upokecenter.com/games/dungeon2/guides/wondermail.php look here
no there isn't but too get zapdos in explorers of darkness you need a mystery part. if you have a mystery part go too amp plains floor 7 and you should find zapdos somewhere in amp plains. it also help if you lead Pokemon is holding a golden mask.