|“||In silencing talk of conflict, Ba Sing Se remains a peaceful, orderly utopia – the last one on Earth.||„|
Long Feng was the Grand Secretariat of Ba Sing Se and the leader of the Dai Li and the secondary antagonist of season 2 of Avatar: The Last Airbender, He was a very charismatic, influential, manipulative, and power-hungry individual. As the Earth King's closest personal adviser, Long Feng hid the existence of the War outside the city's walls while the Dai Li supplanted the king's power over his people.
With the arrival of the Avatar's group to the city, Long Feng captures their lost bison Appa as leverage should they disrupt the delicate balance the Dai Li created. His true motives are exposed by the Avatar when the Dai Li cannot hide all evidence of the Fire Nation's invasion from the Earth King, so Long Feng is imprisoned for treason.
However, the Dai Li are still loyal to their leader, and Long Feng strikes a deal with Princess Azula to give her the Avatar in exchange for power over the city. She double-crosses him when she wins loyalty of the Dai Li, and claims Ba Sing Se in the name of the Fire Nation.
Long Feng was the son of a merchant in the Middle Ring of Ba Sing Se; he rose from his humble origins to become the most feared man in the city as the Grand Secretariat of Ba Sing Se and (more insidiously) the Head of the Dai Li.
As Grand Secretariat of Ba Sing Se, his position grants him a special relationship with the Earth King as his adviser, but in reality the Earth King is but a figurehead of Ba Sing Se's government, and Long Feng truly holds sway over its privatizing affairs. As the war with the Fire Nation spread and refugees began pouring into Ba Sing Se in greater and greater numbers, Long Feng decided to keep all information relating to the war away from the Earth King, thereby appointing himself the sole dictator in matters relating to international affairs.
As Head of the Dai Li, he utilized them as his own secret police to silence anyone who would disrupt the common peace or dare stand against him, secretly imprisoning them under Lake Laogai and using brainwashing techniques to subdue them, just like Jet. This effectively kept the citizens of Ba Sing Se in blissful ignorance and maintained the illusion that there is no war.
He claims to have preserved the last Utopian society left on the planet by covering up all knowledge of the war, when in fact, the totalitarian traits of Ba Sing Se's government are marks of dystopia. His power is so absolute that even the Council of Five cannot break through his stranglehold on the Royal Palace.
Book 2: Earth
Encountering the Avatar
Long Feng Earthbending Ba Sing Se was nearly breached by the Fire Nation's greatest weapon, the Drill, but was destroyed thanks to the intervention of the Avatar and his friends. They arrive in the City to find their bison, Appa, and deliver crucial information to defeat the Fire Nation. These actions conflict with Long Feng's policies in keeping the entire populace oblivious of the war.
Long Feng attended a party being held by the Earth King, for his pet Bear, Bosco. There, Katara and Toph were trying to enter but were initially refused entry by a guard, who rejects even Toph's family seal. The girls ask Long Feng to escort them inside; he accepts. After he uses his influence to get them through the gates, he introduces himself as a government official. He insists on escorting them, but when they meet with Aang and Sokka disguised as servants, he suddenly disappears.
All of the kids are soon discovered by Joo Dee, who appears very frightened that they have defied the orders and entered the palace. Aang is soon exposed as the Avatar, but he quickly smooths things over with a display of his abilities to entertain the audience until the Earth King himself arrives. Sokka is captured and dragged away by Dai Li guards as the Dai Li bind and gag Katara and Toph with Earthbending.
Just when Aang was about to speak to the Earth King, he is confronted by Long Feng, who reveals himself to be the Grand Secretariat of the Earth King and head of the Dai Li. Aang is then led to a room where the others are waiting.
Taking them to a small, private chamber, he explains the true state of affairs in Ba Sing Se: that Feng is in charge of handling day-to-day affairs in the city, including all military matters. The King himself is no more than a figurehead, a beloved icon. Sokka tries to talk about the coming solar eclipse, but is abruptly cut off by Feng. To preserve the culture and utopian life within the walls of Ba Sing Se, Feng explains, no mention of the war is permitted. When Aang threatens to talk and tell everyone about the war, Feng threatens them with expulsion from the city and that the Dai Li will be watching them.
Any attempts to speak to locals about the war would result in their expulsion from the city. He also cryptically remarks that such an expulsion would make their search for Appa difficult. 
Later, he utilizes a mimic of Aang's bison whistle to trick Appa into approaching him. He reveals himself to Appa, and after a swift and powerful Earthbending move, traps the bison underground. 
Avatar Intervenes and Lake Laogai
Long Feng chastises Joo Dee for failing to control the situation the Avatar's presence has created. When Joo Dee confesses her doubt in ability to complete her assignment, he says the words "The Earth King has invited you to Lake Laogai", which places her in a deep hypnotic state. He tells her to await further orders, and then orders a Dai Li officer to “quietly” deal with the Avatar, so as to prevent Aang from threatening the Dai Li's control over the Earth King. Long Feng advises the Earth King. This plan unfolds as a brainwashed acquaintance of the Avatar (Jet) and a hired janitor work to lead the Avatar and his group out of Ba Sing Se under the illusion that Appa had been shipped to a distant island. However, by chance, the group run into Smellerbee and Longshot, who reveal to the group that Jet was captured by the Dai Li. Eventually, the gang concludes that Jet has been brainwashed. After several attempts, they seem to break the Dai Li's hold on Jet. He then reveals to them that he was taken to the secret headquarters of the Dai Li, located beneath Lake Laogai.
Battle at Lake Laogai
Long Feng is arrested. When the group utilizes on this information, Long Feng and a group of Dai Li agents confront them, dropping from the ceiling. He watches as the guards engage in a heated battle with the intruders, then flees the chamber as it becomes apparent that the Dai Li are losing. He leads Aang and Jet, who followed him, into another large chamber and then closes the exit with Earthbending. pursed by Aang and Jet. He offers to drop all charges against Aang and his group and reunite them with Appa if they will immediately leave the city. When his offer is refused, he activates the hypnosis command, forcing Jet to attack Aang. However, Aang manages to break Jet out of his trance by reminding him that he is a freedom fighter, this time freeing Jet of the hypnosis for good. In a fit of rage, Jet flings one of his swords at Long Feng, who dodges and retaliates with a powerful Earthbending move that seriously injures, and in the end, kills Jet. Angrily telling Jet he has chosen his own demise, he departs the scene.
He later appears with a large group of Dai Li on the lake's shore, where they use Earthbending to trap Aang and company. However, Appa emerges from the sky, having been freed earlier by Zuko. He barrels through the stone walls, causing the Dai Li to flee. Long Feng then attacks Appa, arrogantly claiming that he will handle them himself, but his foot is caught in Appa's mouth when he attempts to Earthbend. Appa then flings him out far into the lake, leaving the dictator to nurse his wounded pride and a bitten leg from his embarrassing defeat. 
Fall from Grace
Long Feng and Azula in "The Crossroads of Destiny" Long Feng conspires with one of his own in prison. Long Feng tries to convince the Earth King that Aang and his friends are lying and that there is no war. He clearly has the advantage, until the King was shown the giant Fire Nation drill from "The Drill". He was then arrested and tried for conspiring against the Earth Kingdom. Long Feng was later seen imprisoned, only to be reminded that the Dai Li still remained loyal to him. Shortly after his imprisonment, Princess Azula and her allies infiltrated the city disguised as the Kyoshi Warriors. 
He and Azula make a deal in order to gain control of Ba Sing Se; he gives her control of the Dai Li so as to lead them while he is in jail, and they manage a coup of the city. However, Azula's ruthless efficiency had such a profound effect on the Dai Li, something Long Feng suspected but was unable to stop. When Long Feng was eventually released, he ordered them to arrest her but they hesitated. Azula, having planned this all along, mockingly tells him that though he worked hard for his position, he lacks "the divine right to rule" that she has had from birth. Without the power of the Dai Li to back him up, he was forced to bow before her as she took control of both the Dai Li and Ba Sing Se. When Long Feng contemplated that Azula had beaten him at his own game, she added insult to injury by saying that he wasn't even a player. 
Long Feng's status under the Fire Nation's rule was never known, nor was his fate after Ba Sing Se was liberated. It is highly probable that he remains jailed for his previous crimes, for which he was not properly tried. During Sozin's Comet second arrival, he is briefly mentioned when an angry Azula criticized and banished her Dai Li agents of being late to be by her side, believing they would eventually betray her just as they betrayed Long Feng. 
Personality and Abilities
Long Feng's desire for power stemmed from his upbringing among the dredges of society. He had to struggle up the societal ladder from the Lower Ring straight to the Imperial Palace, developing his skills of manipulation and influence. However, as Azula points out to him later, he was foolish in believing that he could accomplish total control on his own; his refusal to acknowledge power as a divine gift was what ultimately led to his downfall.
As an agent of the Dai Li himself, Long Feng was one of the most powerful Earthbenders in Ba Sing Se. Though he preferred to use other people as pawns instead of fighting his enemies himself, he showed himself a master of Earthbending on numerous occasions. The first was during "Appa's Lost Days" where he overturns a huge slab of ground on Appa in order to capture the Avatar's steed. In "Lake Laogai", Long Feng easily dodges Jet's sword and kills him with a single, well-aimed block of rock.
Long Feng is also knowledgeable in the hypnosis methods used by the Dai Li. By saying the trigger words "The Earth King has invited you to Lake Laogai", he can cause people who have been subjected to the Dai Li's hypnosis, such as Jet and Joo Dee, to obey his every word. The trance can be broken if a strong memory is evoked in the mind of the victim.