look around treasure town after beating the game and talk to mr.mime, go to the dungeon he suggests and beat froslass. Its not too tough to beat that Pokemon. rescue scizor, you will receive the the secret rank.
You need to get through Crevice Cave to rescue Scizor but you need to beat Froslass so you can rescue Scizor. After you rescue him, he will give you the secret rank, which means you can take on special missions like finding the 7 treasures like the Aqua-Monica, Sky Melodica, Rock Horn, Terra Cymbal, Icy Flute, Fiery Drum, and the Grass Cornet. You'll find in these dungeons:Bottomless Sea(B50F), Sky Stairway(50F), World Abyss(B30F), Shimmer Desert(10F), Mt. Avalanche(20F), Giant Volcano(20F), and Mystery Jungle(B30F).
in mystery jungle after you get secret rank
It helps you get all of the legendary pokemon.
he is in amp pains if you have a secret slab and a mystery part
there is a wonder mail code for it
concealed ruins with secret slab or mystery part
He will be at Amp Plains, as long as you have the Secret Slab with you.
the marina resort
Go on the internet and get wonder mail.
miracal sea 3F if ur holding a mystery psrt or secret slab
zapdos is in amp plains on 7F but you need a mystery part or a secret slab
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)