The war broke out after the Fire Nation attacks. Only the Avatar, master of all four elements can stop them. Fearing for the Avatar, the Fire Nation decided to kill every Airbenders in every Air Nomads which will be where the next Avatar born after the death of Avatar Roku. A boy, named Aang leave the temple after he learnt that he was the new Avatar, therefore only he survived the attack. But what if... there's another survivor? And not just ANY survivor, but his twin little sister? How long will it take until they found each other. How did Y/N survived and how did she remain the same even after 100 years of disappearance? Disclaimer: I do not own ATLA. Covers and images belongs to the rightful owner. Some of the storyline is mine if it's not following the animation.