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Sun and Moon are the GSC to X and Y's RBY (X and Y being delibarely very similar to the Gen 1 games in many different ways). Main villains will either be a reformed Team Flare or a group closely related, and you'll end up travel ling through Kalos again halfway through the game.
Considering how heavily he's been featured in promotional materials as of late, Red'll probably be back to take the place of secret final boss again.
