If you release every pokemon you used to defeat the E4, delete your save and pick the starter weak to yours, your game will come back as it was before, only this time with a new professor, Kukui's younger brother.
He's studying pokegods, the first thing you'll notice in the new game is that all of your pokemon are back, and all of the ones who weren't holding items are now holding strange souvenirs.
Climb up the mountain leading to the league and you'll find Grant, he'll tell Kukui's brother that you climbed that high by yourself by believing in yourself and Kukui's brother will give you the A-ring
With the A-ring, you can now turn any pokemon that was holding a strange souvenir into a totem. or colloquially "Pokegods"
