After u beat the game and the credits rolled..
don't think that its over!! but its not over yet!!!!
go to wishcash pond, then u will see alakazam, wishcash, caterpie, metapod, and garnbull
(snubull evolved) he will tell u that he went into a cave there that suddenly appeared, its called luminous cave.... but its narrow only one pokemon can enter at a time....
u cant enter yet... then when u will go on a mission, ur partner will stop and tell u something.... BLAH!BLAH!BLAH!.... and then u can now go to any mission by yourself, or u can now make ur recruited friends ur main character.. then u can now enter the luminous cave, but make sure no body in ur team is joining u on a mission, all of them should be standing by..... some pokemon will only evolve with certain items....