so, what ive done is just write the whole storyline up, but i really dont know how to create a hack or a game, seeing as im not an expert in the area of technology. so this is my storyline:
one day, you are summoned over to your neighbor's, Prof Red (the same guy from RBY), lab. he says that he has heard of some suspicious actions of Team Nebula, a group of bandits that are the remains of Team Rocket. They are trying to reform, and are hunting for Giovanni, their leader, who disappeared years ago, but is in this region. Red asks you to find his colleague, Blue, and gives you a Cleffa for your journey. he asks the same of your Rival, who recieves a Riolu.
on the journey, you will meet Gio, a mysterious trainer who is trying to disband Team Nebula. he is actually Giovanni, and he knows that Team Nebula is bad for the world, and he wants to become good, and he is done with Team Nebula/Rocket. the first admin of TN (team nebula) you meet is Cobalt, but he is soon disposed of after you defeat him. he then joins you in exacting his revenge on TN. he is replaced by Jessie and James. the head is Silver (that's right, Giovannis son, your rival from GSC), and you will fight him later.
TN's overall goal is to wake up Ho-oh on Mt Crimson and Lugia on Mt Cascade, which will disturb Celebi from its sleep. Silver then wants to capture Celebi (on Astrono Island) and use its time travelling powers to restore Team Nebula to being Team Rocket, who were much more powerful.
the game features:
a new region, Neonte, along with new gyms, new E4
a regional dex of 200 pokemon (all from gens 1-4)
johto starters (the same way you get the kanto starters in Yellow, from NPCs)
a battle frontier
as i said, i dont know anything about creating games. i just wrote the storyline by hand. Ive used advancemap once or twice, but thats it. so, i just wanted to get my idea out there. comments, suggestions, and questions are all greatly appreciated