Aelina, the name haunted Aang like no other. A friend that had been killed, not by the fire nation, but by a giant tidal wave. Roku had learned how to make two reincarnations, Aang and Aelina, but Aelina overexerted herself and found out the hard way that if she remained calm, she wouldn't stop her side of the Avatar state, but instead pass it to her other half. She died about the same time Aang froze himself. He had told Katara that there had been two, but one had died, but never anything else. Just that the water avatar had died, and there was nothing Aang could do. Aelina was his best friend growing up, and he missed her dearly.
Aang was feeling terrible, he technically was 130 years old, but looked thirty. Katara and Sokka came in. Sokka was around thirty-four, Katara around thirty. Aang sat up, but started coughing like crazy. He had restored peace, re-created the Air Nomads, and brought unity to the world. And he was dying of a bad case of a cold. Katara rushed up to him. After ten years, their marriage was coming to an end. Katara forced him to lie down, there was basically nothing she could do for him. Aang smiled up at her and whispered, "I know you'll be kind to the next Avatar. I hope they know what they're getting into." After Aang fell asleep, Katara left the room.
While Aang was asleep, Roku talked to him. Roku told him that if he held a stone in one hand, and an ember in the other, he could create two Avatars, instead of the customary one. That was how Aang and Aelina were created. Aang made an ember, and pulled up a stone into his other hand. He felt himself slipping from the world and he let go of everything. Katara entered the room and saw Aang stop breathing, "Sokka! He stopped breathing!" Sokka and a boy named Daren (Aang and Katara's five year old son) rushed in. Daren had a hard time accepting it, "Daddy? Daddy! Bweath Daddy!"Katara took her son down the stairs to where her seven year old (Tarabelle) was. She had another son named Yoru, he was an eight year old Airbender. Her other two were both waterbenders. She took her two waterbending children with her to where Appa was sleeping. She woke him up and told him about Aang. She then persuaded him to take them to the Northern Water Tribe. She knew that her students would need her, and one day in the future, she would meet the new Avatar.
Meanwhile, the very second Aang died, in the fire nation. Thirty-five year old Fire Lord Zuko gazed at his third child. A beautiful girl he and his wife Mai named Serene. Her flame red hair would never dull.
At the same time Serene was born, a boy was born in the Earth Nation city of Omashu. He was born to a woman named Toph bae Fong. Her husband was nicknamed 'The Duke' when he was younger. They named their son Sho, in honor of Jerney's (Duke) father.
It is up to them to fulfill the legacy of the Avatar: Princess Serene and Sho bae Fong.
Author's Note: Can anyone guess what other show the name Sho is from? I realized it a while after I named him!