In the same vein as the previous anon Ephemera also looks a lot like Riku. Perhaps he's Riku's ancestor? I also like the theory of Ava being Kairi's grandmother.
I mean Ephemer/Riku’s not as on the nose as Blaine/Ienzo and…well it can be explained by Nomura liking white hair and blue eyes but still.
I guess I like the idea of ancestors more than I do reincarnation or the same person only time travel. Cause then like they’re connected to the character but they aren’t the character. Granted if you do reincarnation right they are the character but they also aren’t the character but still. Or maybe I’m just opening up to the idea of these characters being connected to already established characters more now that we have three similar looking characters.
Honestly the biggest question here is how long ago did chi take place. They’re always kind of vague about it. It could have happened thousands of years ago or it could have happened a hundred years ago. Who honestly knows.