Deku of the Wind

Bio: Izuku (book 1)

Name: Izuku Beifong 
Bending: Airbender (but he doesn't realize) 
Alliance: Team Korra, Fire Ferrets 

Father: Tenzin 
Mother: Lin Beifong 
Step-Mother: Pema 
Half-Siblings: Jinora, Ikki, Meelo 

Aunt (father's side): Kya
Uncle (father's side): Bumi 
Grandfather (father's side): Aang 
Grandmother (father's side): Katara 
Great-Uncle (father's side): Sokka 

Aunt (mother's side): Suyin Beifong 
Uncle (married to Suyin): Baatar Beifong 
Cousins (children of Suyin): Baatar Beifong Jr., Huan Beifong, Opal Beifong, Wei Beifong, Wing Beifong 
Grandfather (mother's side): Kanto  
Grandmother (mother's side): Toph Beifong 

Profession: Trainer for the Fire Ferrets, Vigilante (The Black Spirit) 

Fighting Style: Izuku uses a combination of highly specialized weapons and multiple fighting styles both bending and non-bending; the result is a highly adaptable and incredibly lethal fighting style that exploits the weaknesses and patterns of his opponents. 

Weapons: 
Bow and Arrow 
Knives 
Dual Boomerangs: A gift from Sokka, Izuku uses two platinum boomerangs with sharpened edges as both thrown weapons and small axes. 
Multiform Sticks: Specially designed by Izuku, these weapons have four forms: their base/storage form has the stick be about the length from his palm to his elbow, and can be used either as melee weapons or be thrown to ricochet and incapacitate enemies (think like the batons used by Daredevil); the sticks can be elongated to double their original length to form escrima sticks (like the ones used by the equals lieutenant or Nightwing), allowing for better reach and defense; the escrima-stick mode can be attached at the base and elongated further, combining into a staff; in it's base form, the weapon can also be opened into a platinum fan (similar to the ones used by the Kyoshi Warriors). 
Grappling Gun: fires the hook using compressed air 
Smoke and Flash Grenades 

Air Bending: Izuku isn't fully aware of his Bending abilities, believing that he is a non-bender. However, he does have a tendency to use his bending subconsciously. Examples of this include: 
Being unaffected by temperature. 
Increasing his running speed and jump height. 
Using Air Bending to assist his aim with his thrown weapons, or affecting the ricochet of his throwing sticks. 
Sensing movement and vibrations in the air around him. 

Personality: Izuku is very cheerful, but often keeps himself closed off from others. He also very rarely talks about his family. Despite what some might think due to his slightly timid nature, Izuku is incredibly intelligent. During the day, he works with Team Korra both as their trainer for Pro Bending, as well as to use his keen intellect to solve problems. However, when he operates as the Black Spirit vigilante at night, he puts on the mask of a cold personality, and mercilessly beats down Triads and Equalists alike. He used to want to be a member of the Republic City police force, but his mother refused to allow him to be a member because she didn't want him getting hurt. In addition to this, he hates how many of the cops have a systemic bias against non-benders and refuse to crack down harder on the triads. The combination of these two things led to him becoming the Black Spirit. Izuku very rarely kills his enemies, but isn't against it if he deems it necessary to save a life. Izuku has a fondness for music, and his favorite band is the rock band 'Heavy Wind', not only because he enjoys their songs, but because the lead singer/guitarist is a non bender: Kyoka Jirou. 

History: The child of Tenzin and Lin Beifong, Izuku was born without a strong connection to the elements, which caused his parents (and he himself) to believe he was a non-bender. In combination with Tenzin leaving Lin to marry Pema and Lin usually being busy with her work as a cop, this lead to Izuku not having a strong connection with his parents. Lin had him trained under multiple non-bending masters, including Sokka, Suki, Mai, and Piandao, all in order to insure that her son would be able to defend himself. During his time training under Sokka and Katara, Izuku met Avatar Korra and formed a friendship with her, being her one normal friend who didn't care she was the avatar and saw her for her. He expressed to her his desire to join his mother's police force in republic city, and they would often joke about meeting up sometime when Korra would be allowed to visit him. Then, she had him learn the basics of the fighting styles of most benders, with fire bending mostly from Iroh and Zuko, air bending from Tenzin (which he was very reluctant to do until Pema basically forced him to), water bending from Katara and Kya, and finally earth and metal bending from herself. However, when Izuku expressed an interest in joining the republic city police force, she told him no. This was partly to try and keep him out of the line of fire of the triads, partly to protect him from other police officers who she already knew had a bias against non benders, and partly because of her own wish she never joined when her mother was the chief. However, she never got around to explaining all the reasons to Izuku, since he ran away to make a living on his own at the age of 10. Years later, as the Black Spirit, he encountered Mako and Bolin, who at the time were under the thumb of the Triads. He attempted to take them down, but the two instead managed to incapacitate him. When they discovered he was the same age as them, however, they hid him from their boss and nursed him back to health, expressing the fact to him that they wanted out of the triads. He later helped them find their own jobs in the work force, and when they formed the Fire Ferrets, the hired him on as a trainer.