Unalaq

Unalaq is one of  the main antagonists of Book 2; Spirits in the Legend of Korra, the others being the Dark Spirits. He is Korra's uncle, the younger brother of Tonraq, and the father of the twins Desna and Eska. Though initially seeming to be a well-meaning individual who offers to train Avatar Korra, his villainous side is revealed when it's learned that he was the one responsible for the banishment of his Brother Tonraq from the Northern Water Tribe.

Past
Unalaq was born to the Chief of the Northern Water Tribe. As he was growing up, Unalaq took a fasination to the Spirits, as well as their ways. He was always jealous of his older brother, so to become next in line, Unalaq devised a plan to get rid of his brother. Unalag hired a small army of Barbarians to attack the Northern Water Tribe. After they get Tonraq's attention, they were to retreat to a Spiritual Forest, to which Tonraq destroyed the forest to find them. That night, angry Spirits attacked the Northern Water Tribe. With his knowledge of the Spirits, Unalaq managed to subdue all of them with ease. Afterward, Tonraq admitted to his mistake. Enraged, the chief of the Northern Water Tribe banished Tonraq to the Southern Water Tribe. With his brother banished, Unalaq become next in line to become Chief of the Northern Water Tribe.

As years went by, Unalaq became the Chief of the Norther Water Tribe, and eventually had two kids, Desna and Eska. He eventually found out that his brother was the father of the Avatar.

Becoming Korra's Teacher
Six months after Korra defeated Amon, Unalaq came to "visits" his family at the Southern Water Tribe, while attending the Glacier Spirits Festival. He stated that he was disappointed on how the Southern Tribe forgotten about the Spirits, and certain tratitional ways. During the Festival, Unalaq was attempting to convince Korra to be his student so he could teach her about spirits and the Spirit World. But both Tenzin and Tonraq didn't want her to be taught by him. That night, an Angry Spirit attacked the festival. Korra and her friends were proven to be no match for the Spirit, but then Unalaq appears out of nowhere and managed to tamed the spirit. Impressed by Unalaq, Korra accepted his offer, to much of her father's disaproval. Unalaq told Korra that in order to calm the Spirits, they would have to journey to the Everstorm to restore the Southern Lights. After a while, Unalaq, Korra, her friends and Tonraq reached the Spritual Forest. Unalaq told that She was the only one who could enter the forest.

Controling the Southern Water Tribe
After Korra successfully unlocked the portal between the Human World and the Spiritual World, Unalaq told her that it wasn't over yet. The next morning, Soldiers of the Norther Water Tribe arrived at the shores of the Southern Water Tribes. Unalaq told Korra that more work needed to be done before the two tribes were truly reunited again. While they were disgusing this, the soldiers created blockades to prevent and citizen of the Southern Water Tribe to escape. This caused tension between the North and the South. Unalaq stated that this was necessary to unite the two tribes. One night Southern Rebels attacked Unalaq in his sleep and attempted to kill him. Korra managed to rescue him and capture all of them. Korra recommended a trial to the assassins, to which Unalaq agreed with her decision. The next morning however, Unalaq, along with a small group of Northern Water Tribe Soldiers appeared at the door of Korra's home. Unalaq stated that Tonraq and Senna are under arrest for attempted assassination.

The Trial
Korra's parents and the Southern Rebels were put on trial. Unalaq told Korra that persionally hired the "fairest" judge he could find; Judge Hotah. Despite this, all except for Senna were found guilty on all charges, and were sentence by death. Enraged Korra threated to end the Judge's life. with that gesture, Unalaq managed to "convince" the Jedge to reconsider sentence. With that, Hotah lower the sentence to life in prison.

Unalaq Revealed
Later that day, Korra confronted Hotah. He told her that the court was rigged by Unalaq. He also told her that Unalaq did this so he could earn Korra's trust and get his brother out of the way. After finding out, Korra and her friends went to Tonraq's prison cell to break him out, only to find out that his cell was empty. Just then Unalaq appeared and told her that both Tonraq and the rebels were sent away via a ship heading to the north. Confronting Unalaq about his selfish and underhanded deeds, Korra renounced him as her teacher and demanded that he recall the prison ship, reminding that he still needed her to open the northern spirit portal. However, Unalaq confessed that he no longer needed her, revealing he had only been exploiting her into thinking that. This caused the Avatar to attack him out of sheer anger and fury. Korra, Mako confronted Unalaq, but Unalaq proved to be a powerful waterbender. After a while, Korra unleashed a powerful gust of wind to push Unalaq back. With that distraction, Korra and her friends, ran off to save Tonraq and the rebels.

However, it was revealed that Unalaq still needed Korra to open the northern spirit portal. So he sent Eska and Desna to find and capture the Avatar alive.

Powers
Unalaq is a powerful waterbender. He also has the ability to calm spirits.

Trivia

 * Unalaq is extremly similar to Councilman Tarrlok:
 * Both are charismatic male waterbenders with ambiguous motivations that claim to be well-intentioned
 * Both use their claims of being well-intentioned as a justification for oppressing others
 * Both manipulate Avatar Korra for their own ends
 * Both are the brother of another main character in the show (Amon and Tonraq respectively)
 * Unalaq is also similar to Fire Lord Ozai, as both were ambitious power-hungry siblings who took a title of leadership that was originally intended for their brother. Both are also arrogant and powerful benders. Perhaps fittingly, in Varrick's propaganda film Unalaq is portrayed as looking very similar to Fire Lord Ozai, his outfit also featuring a similar high collar.
 * If Unalaq had not gotten his Brother Tonraq banished from the Northen water tribe, then Tonraq would have never married Senna and Korra would have never been born and the next Waterbending Avatar would have been someone else.