I Got carried away with these two, lol.

in the au, Flash is an airbender who grew up in the southern water tribe and Sunset is rogue fire bender and fugitive in the fire nation. They’re traveling companions who have been living and moving together for a couples years now.
(context, in this au the airbender genocide did occur but it wasn’t complete, so the temples are much much less populated and there’s a lot of air nomad diaspora from them scattering and trying to assimilate in other places.)

Sunset has both sun warrior heritage and water tribe heritage.
Sunset is an excellent fire bender with a significant amount of power and training. She was once a master’s prodigal student, training near the fire sages, but she ended up abandoning her training and going on the run. Overtime her form has adjusted to incorporate for and elements from other bending. she also has a strong connection with the sun, often doing her katas under the full light of it. she can also energy read with her firebending.

Flash is an airbender with a non traditional style, usually using a lot more elements of water bending, fire bending, and nonbending martial arts forms when he bends. He’s learned air bending basics from some traveling masters in order to build off of, but mostly he tries to adapt to his style, as he did not grow up with the traditional disciplines. He is also incredibly gymnastic and flexible, which plays into how he moves. A lot of the time he uses his air bending as a way to support sunset’s fire bending, boosting the flames by feeding them and carrying them on the wind. he also uses his Bo staff a lot, as he was trained with it as a weapon before he started using it as a bending aid.

these two travel around together with rey and banana, with rey in this au being a mongoose lizard and Banana being a polarbear dog, They are both their respect owners mounts.
Currently, they travel around the fire nation together, trying to find a way to get off the continent. They do everything they can to support and protect eachother, and each considers the other their closest friend.