Evolved Neon

What will happen when a stranger happens to pop out of now where and bares a striking resemblance to a Pokemon. And whom Crystal declares is her cousin? And why does she seem to have a strong connection with legendaries? And what will happen when a leader is needed for the dexers?
Now all the regions are put in danger and all the pokedex holders must band together to defeat the threat. Will this stranger be the one who is most important?

Notice: this fanfic is of the pokemon adventures manga, not of the anime or cartoons. All the characters are from kanto to Sinnoh.