Purchasing the older stones would be a huge relief, but from what the users who have the games are saying, that apparently isn't possible. :c
Which sucks, because I would legit buy fifty of each.
The Achroma Machine seems to affect the Crustle in Seaside Cave, from what serebii has revealed.
Maybe the forgotten item has something to do with Ghetsis? Maybe even Genesect. No idea, but I know I'm excited for that Round and Shiny charm. They'll be a hard task to get, but I can't wait!