I would bet that the end of the next game will be like how the TTGL movies change the original TTGL ending. Everyone will become a Cetra God and combine to defeat Super God Sephiroth. They already teased it with Tifa. She will merge with her dad, Barret will merge with Dyne, Cait will merge with Dio, Cloud will merge with Aerith, and they will all do a Super Holy to finish off the game. You'll have to press L2 and R2 87 times in a row to pull it off.
_foolmo_
he says listen to my story this maybe are last chance