The Second Wind

In the distant future, mastering all four elements is a calculated science. But when a temporal rift throws eighteen-year-old Albert back into the brutal era of the Hundred Year War, the cosmic laws of the past violently strip away his fire, water, and earth. Left with nothing but his birth element of air, he crashes directly into the Western Air Temple-and straight into Team Avatar.
Aang thinks he's found a miracle: a surviving Air Nomad from a hidden enclave. Zuko thinks he's a highly dangerous Fire Nation spy. Albert is just trying to survive with his ribs bound and his mouth shut. Trapped behind enemy lines during the countdown to Sozin's Comet, Albert must navigate a lethal double-life. If he reveals his futuristic origins or his physical identity as a trans man, he risks unraveling the timeline and shattering the Avatar's fragile hope. But in a camp full of the world's most powerful benders, secrets are the hardest element to control.
A canon-divergent ATLA original story by Dirtaria.