>>34092797>Thorough worldbuilding for the alternate realities of each RR boss, which each of them interesting subplotsCan you imagine the RR boss Giovanni in his castle with warp rooms to each other leader? You can go into each one, find the respective leader, and beat them in order to keep them away from Alola.
You could actually defeat the baddies from all gens and save their worlds.
>Archie and Team AquaYou arrive through the warp hole to Sootopolis City - the city is heavily flooded, with rain pouring down in torrents, submerging the Gym and lower houses. Citizens are scared. One of the higher houses is occupied by Archie and a gang of Team Aqua goons. You defeat his Primal Kyogre, triggering his downfall and stopping the rain.
>Maxie and Team MagmaSootopolis City has crumbled a little, harsh sunlight, the underwater cave is blocked and the city's water has dried up. Same thing with a Maxie Primal Groudon battle.
>CyrusEncountered in the Distortion World, where he has control of Giratina.
>Ghetsis and Team PlasmaEncountered in his BW castle, where you also encounter an imprisoned N.
>Lysandre and Team FlareEncountered in the Secret Team Flare HQ. Battle the Team Flare Admins and stop Lysandre.
Finally, after you finish them off, chase Giovanni back into a revamped Silph Co / Rocket HQ, where you have to fight through Grunts to get to his room and finish him off in a high-stakes, high-level battle.
Accessing these snippets of other regions would allow the player to:
>find region-specific legendaries in a realistic way>evolve pokemon into their Kanto forms>if you allow small areas for fishing/grass patches, find lots more pokemon>nostalgia bonus points 
