A Special Bender. (ATLA-Zuko)

Aang has an older sister, Yihn, who is able to bend the element air, along with light and energy. When Aang left the temple, upset, Yihn chased him on her own flying creature, a Griffin named Ahaan. When Appa fell into the water with Aang, so did Yihn and Ahaan. The only difference, is that Yihn saved Ahaan and herself by making a large air pocket for them, much like Aang did, and the four were frozen in the water for 100 years. Yihn was only 14, 2 years older than Aang, when they were frozen, but for some strange reason, she was found and 'rescued' two years before her brother is found. Ahaan and her are taken by Prince Zuko and his Uncle, and after hearing their explanation for being in the south pole, she made the choice to keep her airbending secret, and mostly used her light and energy bending, not to mention hand-to-hand combat and weaponry. But being raised alongside her brother, even though she was a girl, she does not use violence against others unless completely necessary. This is the story of Yihn, and how she fell in love with a Fire Nation Prince, and searched for her little brother.