Sonna is a supporting character in AMJ.
Sonna was a gifted archer who served under Macai's 31st Company. Macai immediately noticed her skills during the archer training drills. Sonna's talent in training and on the battlefield quickly lead to her being selected for several dangerous missions. When she first joined Macai's unit, she was sixteen years old. During book 1 of Avatar: The Last Airbender (ATLA), Sonna was 17 years old. That made her one year older than Zuko, one year older than Kanna, three years older than Azula, and two years older than Macai.
Early Childhood
Sonna grew up in a village called Ullon. She had three brothers and one younger sister. The town was located on the Western end of Fire Nation territory and had many hills in it. Much of her childhood consisted of manual labor and homeschooling. Sonna would later go to a standard high school before graduation. The lack of interaction with her peers for many years made her more introverted. Sonna enjoyed reading and writing in her free time. Unlike most fire nation girls, Sonna also learned how to fix things around her house.
Because she was a girl, her father didn't allow her to carry and lift heavier objects. That work was reserved for her brothers. Because of this, Sonna was tasked with hunting animals. Usually, the father wouldn't permit a girl to hunt up close either. However, Sonna was naturally the most gifted archer in her family, and she would later discover that she was the best archer in her village. Sonna hunted several animals and learned how to hit them from different elevations. Sonna could fire her arrow from a distant hill and hit an animal that was twenty or thirty meters away.
Sonna went on to win several archery competitions in Ullon. This built up a reputation for her before she left. This gave the girl with humble beginnings something to be proud of. Because of this, Sonna was selected as one of the newest recruits of Macai's unit. However, Macai did not know this. Macai only personally selected a few people that he knew (Kett, Kanna, and Dade). Commander Kenshin (Macai's commanding officer, who didn't work directly with him) was the one who decided to send Sonna to Macai's 31st Company.
Abilities
Sonna was just as valuable as many talented benders and could defeat several benders by shooting them from a distance with her arrows. Sonna could shoot three arrows in the time that the average Fire Nation archer could fire one. She also could five it at least five times faster than most other archers. Sonna had great vision and perception; allowing her to target enemies more quickly than most archers. The young woman also had sharper senses than most nonbenders and benders alike.
Sonna was great at flanking her enemies and attacked her enemies from different directions. Sonna had the best tactics in her unit. Even better than Macai. Her direct battle tactics were something that could even catch Azula off-guard. Because Sonna focused so much on firing her arrows, her hand-to-hand skills were lacking in comparison. Sonna also was not proficient with melee weapons. On the other hand, Sonna learned how to kick very well and was great at dodging attacks.
As good as Sonna was, she needed to stay in the back on her squad in most engagements. Because Sonna was an outstanding archer, she could still take down a couple of warriors in close combat. However, she was much more vulnerable in brawls than benders or warriors who specialized in close combat engagements.
Personality
Sonna was a disciplined, adaptive, loyal, and supportive young woman. She was more introverted than girls like Kanna, Azula, and Ty Lee. Sonna had a strong love and admiration for animals.
Legacy
Sonna became one of the most feared and respected archers in the Fire Nation. She would later be posted on several Fire Nation posters. She would often be one of the central figures in a picture of Macai's unit. However, she would not be noticed as much as Macai, Rosh, Kett, or Kanna. Sonna was posted in several nonbender legacy postures. Such posters would have several notable nonbenders (usually outside of Ozai's Angles since they had their own posters).