The story of Rahir, an ancient avatar who hails from the Earth Kingdom, as he embarks on his own journey, seeking to help establish a world in which benders, non-benders, spirits, and citizens of other nations can coexist in harmony, while dealing with numerous threats to the peace he aims to create, and even threats to his own existence.

This is my own interpretation of a story of an avatar that existed long before Aang or Korra, around the time when the avatar world was just being established. I'll mostly be following ATLA lore, since that allows for more freedom to add my own touch to the world while trying to maintain what made everyone fall in love with the original series in the first place!