Tufen is a book 4 villain in Avatar: Macai's Journey. Tufen was the waterbending leader of the Disciples of Justice. This made him one of DOJ's enforcers along with Beruto, Karanga, Haresh, and Voren.
Background
Before Tufen joined the Disciples of Justice, he was a farmer in a rural part of the Eastern Water Tribe. Tufen's life was quite simple at first, he looked after livestock and used his waterbending to harvest crops. One day a gang attacked his farm, killed his parents, and took him hostage. Tufen's and his younger sister were kidnapped. At the time, he was only 11 years old.
Tufen concentrated and used waterbending to efficiently kill two of the gang members. The other two attempted to stop him but were swiftly dispatched. Tufen's sister was disgusted by his actions, but the young man declared this as a necessary intervention. The siblings returned to their farm and continued to run it as they remembered what their parents taught them.
Tufen still had never been trained in the art of waterbending as both his parents were nonbenders. A distant battle occurred where a company of Fire Nation forces looked to gain a foothold in the Eastern Water Tribe. A squad of Fire Nation forces would later patrol Tufen's land, he was now 16 but had been practicing his fighting moves in solitude. The teen mercilessly butchered the soldiers as he looked to defend his land.
Tufen's sister wished the Eastern Water Tribe had a more powerful military that could protect them from the Fire Nation and the gangs. But Tufen had a different response. He attributed the death of his parents to society not preparing inhabitants for the harshness of life and said if his parents prepared more themselves instead of trusting in an ineffective tribe; they have survived. Tufen also took note of how many people died from raids from the Fire Nation and defined them as "glorified and more well-equipped gang members".
To Tufen, any great structure or system of men only enhanced chances of them abusing others. Gangs often abused individuals, stragglers, or families that did not link up together for strength. Tribes potentially could do the same but were less likely to because of limited size and a need for stability. Kingdoms and armies had greater opportunity for abuse because of their sheer size. For this same reason, Empires were even more dangerous.

Tufen had limited trust in people and believed that individuals should be able to make decisions on their own terms. Because of this he began to resent higher levels of Human authority.
After Tufen turned 17, he created his own group of vigilantes called "The Free Men". The Free Men would patrol their rural pastures and take down gangs and raiders throughout their territory. Many members of the group were similar to Tufen and had been badly impacted by marauders. Some of the local tribes began to see this group as a threat because of their belief in self-sufficiency and independence from other forms of authority. However, the tribes also benefited from their fighting because it gave them opportunities to build themselves up, gather more recruits, and gain power since they had less marauders to fight against.
Three tribes would later band together and attack the Free Men's camp. All of the members except Tufen and two of his closest allies were killed from an ambush. One of them eventually bled out and Tufen's healing was not enough to prevent the gruesome injuries dealt to his companion. The other admitted he had previously been skeptical of the waterbender's views before but came to realize he was completely right about governments and how they are innately abusive. Tufen came to believe any and every government would eventually become corrupt even if it had a just leader at some point. Part of this was due to the fact that governments were the products of imperfect Humans who often have malicious motives.
Tufen exiled himself to a remote part of the Western Water Tribe, where he hoped he would stay out of danger. It would no longer be safe for him to return home. As he waited, one day Zerrel would seek him out. Zerrel came with Karanga and Beruto. Zerrel asked the hermit if he would be willing to get himself back into social affairs. Tufen said he was done telling people how to live and the best way to live was by doing what he was, surviving independently from the lies of a fake society. Zerrel informed Tufen that he was looking to recruit him for a greater cause one that can avoid the greatest risk to all people.
Zerrel feared a new global government would rise or a group like the Fire Nation would become so powerful that it would eventually take over the world if technology was allowed to advance as it was. Zerrel had a plan to destroy all of the governments, starting with the most powerful and to create a belief that might never die. The man's hope was that every 1,000 years, rebels from a new generation would destroy the most powerful groups and the technology they possess to create an opportunity for a freer and more competitive world in the next generations.
Zerrel believed at the moment, governments were the single biggest threat due to their monopoly over the power to kill, destroy, and create compared to other Human institutions. However, he admitted that in another timeline, the exact threat could change. Still, it would be important to reset so Humanity would not become powerful enough to destroy itself or for elites to over impose themselves on generations that would not be able to fight back. Tufen admitted that some people will always be abused but that people at least have a chance to fight back in the current system, however he believed technology and advanced governments could destroy that ability.
Tufen concluded that he was destined to join Zerrel on his quest to save the earth by destroying the Fire Nation and Earth Kingdom regardless of who was in command of those institutions. He started as a simple member within the Disciples of Justice but would quickly earn Zerrel's trust as he risked his life on various perilous missions and managed to increase Zerrel's following. Tufen also made moves to gain allies from others who had similar views throughout the world including some people in high offices.
Personality
Tufen was straightforward, efficient, and fearless.
Abilities
Like many waterbenders Tufen was known for his smooth attacks. Unlike most waterbenders, Tufen preferred ice bending attacks and used them more frequently than most of his waterbending moves. Still, Tufen was incredibly efficient and practical in combat, and he tailored his fighting styles to his opponents. When he fought Macai, he used water attacks because he knew Macai struggled more to keep up with large water attacks compared to the other elements and water attacks often were generated a bit faster than fire, stone, ice, and sand strikes.
When Tufen used water, he usually shot freezing cold water at his opponents. In a fight with Kett, Tufen used more water attacks than usual because of Kett's defensive and ranged nature. Tufen needed a way to keep him busy. Tufen also used water attacks while taking on several elite Dai Li agents by flooding a tunnel that they were in.