Amon

Amon, born as Noatak, was the charismatic and mysterious leader of an anti-bender revolutionary group known as the Equalists. Their ultimate goal was to introduce equality for all by permanently ridding the world of benders. A nimble, agile, and stealthy fighter, Amon was fearless in facing his opponents, regardless of their powerful bending skills and abilities.

Claiming to be an innocent nonbender to whom the spirits granted the ability to remove a person's bending permanently, a power previously demonstrated only by the Avatar, Amon gained the confidence and support of many people with the same ideals. However, when the complete conquest of Republic City by the Equalists became imminent, Amon's true identity was exposed to the public by Avatar Korra. In actuality, he was a prodigious Northern Water Tribe bloodbender, son of the escaped crime boss, Yakone. Alongside his younger brother, the former councilman, Tarrlok, Amon was unknowingly shaped by Yakone to be a tool for his revenge against the Avatar.

Background
Noatak was born in the Northern Water Tribe to Yakone and his wife, as the older brother of Tarrlok by three years. Growing up, he was a good-natured child who always looked out for his younger brother and wanted everyone to be treated fairly and equally.

When Noatak and Tarrlok both discovered they were waterbenders, Yakone trained them ruthlessly to develop their skills. When Noatak was ten, Yakone took his sons on a supposed hunting trip far from their home, where he revealed his true identity as a Republic City criminal and explained to them the power of bloodbending. Claiming that their family had the strongest line of bloodbenders in history and with the intent of making his sons bloodbenders of the highest caliber to exact his revenge against Aang for stripping him of his bending, Yakone trained them secretly during every full moon to use their bloodbending on animals, such as yaks and wolves. Reveling in his newfound power, Noatak also mastered Yakone's unique psychic bloodbending technique by the time he was fourteen. As a bloodbending prodigy, he carried the burden of all his father's expectations and over the years, he became cold and detached.

Eventually, Yakone ordered his sons to bloodbend each other, which Noatak did with great ease, ignoring his brother's screams of pain until Yakone ordered him to stop. When Tarrlok refused to bloodbend Noatak, Yakone became angry, calling him weak, and prepared to attack him as punishment. However, Noatak defended his brother by bloodbending his own father, stating that Yakone, having been stripped of his waterbending by the Avatar, was actually the weak one and that they were his children rather than his "tools of vengeance". He subsequently offered his brother to join him to start a new life away from Yakone, but Tarrlok declined, arguing that he was worried about their mother, thus causing Noatak to agree with their father's opinion of Tarrlok being weak. After flinging Yakone in the snow, Noatak ran off into the blizzard, prompting Yakone and Tarrlok to search for him in the following days; they eventually assumed that he had perished in the storm.

At some point in his life, Noatak discovered that he could use his bloodbending skills to strip a bender of their ability. He assumed the alias of "Amon" and became the leader of the Equalists, an organization striving to rid the world of bending. To garner sympathy and hide that he was a bender himself, Amon claimed that he was born on a small farm to a poor family of nonbenders who were being extorted by a firebender. When his father had supposedly confronted the bender, he and the rest of his family were murdered and Amon's face was left scarred from the attack, forcing him to hide behind a mask ever since. He also claimed that he had been granted the power to remove bending by the spirits because they believed the Avatar had failed the world and wanted him to usher in an era of equality.