If you've made it through and have followed this Guide to the nth degree, congratulations, you've finished the game. Outside of finishing your Pokedex and "Catching 'Em All", there really isn't much left for you to do. You can build your Festival Plaza, sure, as well as Trade and Battle other player online. But that's it!
And that leaves the question: Where does the Pokemon Company go from here, after one of the most unique and amazing Pokemon Games yet? And actually, there are a number of opinions and rumors floating around about what will come next. The most obvious thought is a sequel game to Pokemon Sun & Moon. Most people believe this would come as either Pokemon Space or Pokemon Stars, obviously with Necrozma as the main Pokemon, the Cover Legendary of such. However, with the most recent example of Pokemon X & Y, Pokemon Sun & Moon, too, might never receive a sequel. This very well might be a thing of the past with the Pokemon Franchise.
Or perhaps some Pokemon fans will receive their wish and the Fourth Generation Games of Pokemon Diamond, Pearl and Platinum will receive an update in the form of a remake? Perhaps this will even take place with Arceus as the main focus / Cover Legendary Pokemon? Its been almost a decade since their original release, and it just might be Time to finally do it if no sequels will be made for Pokemon Sun & Moon.
Whatever the case, the odds are still in favor for more New regions and more New Pokemon yet to still come and be discovered! Alola!