@RyouguI can't give a prelude, exactly, but I can do the next best thing, which is a bit of a teaser for the person in charge of the in-story tournament and main plot point:
For those familiar with both Pokemon X/Y and the original Yu-Gi-Oh! series, imagine what would happen if Diantha and Kaiba had a baby.
That's all I'll say on the subject for now.
@RaddumCard seems a little silly since it can just pop itself to go +1, but it looks fine otherwise.