Fanfic prompt: Aang sees a vision of the future, which gives him the hope to keep going.
Feel free to make something of it!
Avatar au: for whatever reason (Ursa takes off with Zuko to find somewhere safe, Iroh takes him around the world, he gets banished to the pole, etc) Zuko comes to hang out at the South Pole and becomes unlikely friends with the water kids. It obviously starts out rocky, but gets there eventually.