A while back I learned about this cave in BW2 that I had no idea existed and thought it was ripe for submas lore.
https://bulbapedia.bulbagarden.net/wiki/Cave_of_Being>They say the deepest part of the cave leads to the Sinnoh region. They could have brought this back as an excuse for Emmet to end up in Hisui. Man, the more I think about all the possible ways the poke-world has for him to find out what's going on and get his bro back from the past, the harder it is for me to believe Ingo could stay there for 10+ years unles it's just time not being parallel or whatever. There's tons of regular-ass trainers on the Battle Subway with legendaries, Emmet has no excuse for not going over to have a chat with Uxie or something, let alone punch Arceus.
At least the cave makes for good fic fuel.
