>>14680154Don't forget catching Zygarde and Mewtwo.
Also, I think it's pretty likely that there is more to the post-game than meets the eye. There is a LOT of suspicious things such as the ghost girl, chamber of emptiness, completely barren alleyways that look like arenas, power plant doors, mysterious statue from another region, the mysterious message on the back of the train station sign, the editor that has gone missing etc...
Even if these things aren't currently accessible, I'm sure they will be in the not too distant future by means of updates, DLC or events.
We haven't seen everything. We just can't datamine the games to confirm it.