What if Sozin died with Roku (or maybe instead of).
They’d be no war so what would the characters be doing? Aang would probably still have run away but with less consequences. Katara would have had waterbenders to learn from in the south pole. It’s doubtful Ozai would be fire lord but would he be as bad as he was? And it’s very doubtful Toph’s life have changed at all.
I had a vague idea of there being some sort of evil organisation working in the shadows of all four nations (maybe started by Sozin) kind of like an evil order of the white lotus.
Of course I can’t think of what else to do with it so it on the stories-I’ll-never-write pile.