What would happen to the world and the Lyoko Gang if Xana actually beat them? Would they give up? Or would they fight for their freedom? It is up to you and what you write. Though this is was I think that your story should follow:

1. Any rating is acceptable

2. At least 3 or more chapters at a decent length plz!

3. You may let the story happen during any season.

and..

4. If people die PLEASE keep all of the Lyoko Gang alive.