>>38460934In Alola you've Magearna, Marshadow & Zeraora. Each one could introduce a new island based on another location in the Pacific Ocean and be accessed from the Aether Foundation acting sort of like the Sevii Islands.
For Magearna it could be quite simple being a similar premise to Diancie's with some remnant sect of the Aether Foundation attempting to track down the Mechanical Pokemon in some old Port City that was once an old marine fortress with the entire plot of the island being around the city itself with urban Pokemon and no rural areas.
For Marshadow it might involve visiting the Mirage Island which the Aether Foundation had been trying to track down believing it to be a secret paradise for many rare species of Pokemon, the player visits the island and indeed finds that it is a paradise for these rare Pokemon (mainly Pokemon not found in Alola or Ultra Space) and there's a small village on the island that was developed by a relative of the old man from RSE who could see the Mirage Island. The player would find that some character in the village had been cursed by Marshadow, distinguished by them having an unnatural second shadow and the player would have to help them lure Marshadow out by completing some ancient ritual in some old ruins buried beneath the island.
For Zeraora perhaps it's hidden in a flying artificial island by some new antagonist who uses Zeraora secretly to power the flying island, the player uncovers the secret by exploring the artificial island and in freeing Zeraora causes the artificial island to crash near a completely separate island which the player can use to visit the artificial island again to find various extraterrestrial and inorganic Pokemon that don't appear in Alola as well as the island it crashed into housing some unusual Pokemon as well, maybe even serving as the home of Samson Oak.
Pt.2