Aang (Voiced by Zach Tyler Eisen) is the fun-loving, 112-year-old protagonist.
Aang was born to two unnamed Airbenders in 12 BSC who gave him to the monks at the Southern Air Temple. As an Air Nomad, Aang had traveled extensively around the world. During his childhood, Aang was housed, raised, and educated at his home, the Southern Air Temple, under the custody of Monk Gyatso, who served as both a father figure and a counselor for Aang. As a child Aang was a member of the Air Scouts, where he learned essential skills such as how to tie reins to a bison's horns with the bison horn not. When Aang turned six years old, he and several other young Air Nomad boys were taken to the Eastern Air Temple where they each chose a sky bison as their lifelong companion. Aang approached his soon-to-be pet sky bison Appa and offered him an apple, which Appa accepted, thus marking the start of their friendship. Aang had always been able to excel with any new bending moves he learned; at the age of six, he was a better Airbender than children twice his age, and by the age of ten, Aang had proven himself to be better than his own teacher.
While still a young boy, Aang had unconsciously revealed himself to be the Avatar when he chose the four Avatar Relics from thousands of toys to play with. In his childhood, Aang also visited the other Air Temples, as evidenced by his obvious familiarity with the Western Air Temple, as well as cities in the then-peaceful Earth Kingdom, such as Omashu, where he developed a lasting friendship with the good-natured but eccentric Bumi; he even bonded closely with children in the Fire Nation, like Kuzon, with whom Aang claimed to have gotten "in and out of so much trouble together." Due to the signs of a possible war approaching, Aang was told about his status as the Avatar at age twelve, four years earlier than the traditional age of sixteen, after exhibiting prodigious talent with his native element, Air. Aang felt burdened by his status and came to spend more time practicing Airbending with the monks rather than playing with his friends as he was used to. Monk Gyatso was the only one to show understanding to Aang's burden, having been good friends with Avatar Roku, Aang's past life, and tried to help ease Aang through the transition from childhood to adulthood by providing Aang with balance through fun during the upheaval in his life.
However, after learning that he'd be sent to the Eastern Air Temple in order to complete his Airbending training far away from Monk Gyatso, who other monks thought was too soft on him, Aang attempted to run away on his flying bison Appa. Shortly after running away, Aang and Appa were caught in a storm, crashing in the water and being swallowed by the waves. Aang saved himself and Appa while semi-conscious by entering the Avatar State, freezing the two in a sphere of ice by using a combination of Airbending and Waterbending. The Avatar State kept him alive, albeit not fully conscious, in the iceberg for about a hundred years.
Book 1: Water
- Main article: History of Aang (12 BSC - 100 ASC)
Prior to being freed by Katara, Aang was in an age-defying Avatar State inside an iceberg.Added by Thailog One hundred years later, Aang was found and freed from the iceberg by siblings Katara and Sokka of the Southern Water Tribe. He quickly befriended them and almost immediately attracted the attention of Prince Zuko, who was to capture him by order of his father, Fire Lord Ozai. The three set out to find a Waterbending master who could teach Katara and Aang, evading Zuko's attempts to capture them along the way. While helping Senlin Village, Aang crossed over to the Spirit World where he met Fang, the animal guide of his predecessor, Avatar Roku. He was instructed to visit an Avatar temple on Crescent Island during the Winter Solstice so that he could talk with Roku. Despite a run-in with most of the Fire Sages, a group now loyal to the Fire Lord, Aang managed to speak with Roku, who warned him about the impending arrival of Sozin's Comet, which would grant the Fire Nation enough power to win the War.
Roku urged Aang to master the three remaining elements before summer's end, when the comet was due to arrive, or he or anyone else would never be able to restore balance to the world. Aang was later captured by Admiral Zhao and Zuko came to his aid under the identity of the Blue Spirit, freeing the former so that he could capture the Avatar himself. Upon the group's arrival at the Northern Water Tribe, Aang was displeased to learn that his teacher, Master Pakku, wouldn't teach Katara, due to the tradition of not teaching females to use their Waterbending to fight. Katara was able to change Pakku's mind, and they both began to learn under him. The period of calm was brief, as Zhao, commanded an attack on the Northern Water Tribe with a large fleet of ships. Aang found the situation overwhelming and decided to seek guidance in the Ocean and Moon spirits, patrons of the Northern Water Tribe. Aang learned through a spirit named Koh that the spirits were in the mortal world, but his body was taken by Zuko in the process. Aang's friends managed to rescue him, but not before Zhao arrived at the Spirit Oasis, the lair of the spirits, and killed the Moon spirit, who was the source of power for all Waterbending. Determined not to fail the Water Tribe, Aang merged with the Ocean Spirit and proceeded to wipe out the rest of the Fire Nation fleet. After all was over, the group left the North Pole. Aang was now learning Waterbending under Katara, whose fierce determination allowed for a quicker rise to mastery.
Book 2: Earth Edit
- Main article: History of Aang (Spring 100 ASC)
Aang is struck down by Azula as he enters the Avatar state.Added by Thailog Aang and the others were left near an Earth Kingdom base, from where they were to be escorted to Omashu, to be taught Earthbending by one of his living peers, King Bumi. Due to a misunderstanding with the general responsible for the base, who wanted to forcibly draw the Avatar State, the group decided to go to Omashu by themselves. Upon arrival they learned that the city had fallen under Fire Nation control. They tried to rescue Bumi by trading him for the new governor's son, who accidentally left the city by following Momo. However, Zuko's younger sister Azula interfered saying the Fire Nation would be trading a powerful, Earthbending king for a two-year-old. At that, Aang fought Azula, who also decided to capture him. Bumi told Aang that he needed to remain in Omashu and instructed the young Avatar to search for an Earthbending master who waited and listened to the Earth before attacking. While lost in the Foggy Swamp, Aang had a vision about a laughing girl and a flying boar. Upon reaching the city of Gaoling, they were handed a flyer with a coupon for one free lesson at Master Yu's Earthbending Academy. After attending the lesson, Aang learned about a tournament that housed the best Earthbenders in the world. The threesome set out to search for a supposed underground Earthbending tournament, hoping to find a good teacher. After watching many rounds, they witnessed the final fight between one of the popular contestants and the current champion, a little blind girl. During her match, Aang noticed that the girl's laugh matched the one he had heard in his vision and that she waited and listened before attacking, thus easily defeating her opponent. The ringmaster offered a sack of gold pieces to anyone who dared to face the "Blind Bandit". Aang accepted that challenge in order to talk to the girl, but she ignored him.
The group later learned that the girl belonged to the Bei Fong Family, whose symbol was a Flying Boar. They went to the estate and Aang introduced himself as the Avatar. He learned, however, that Toph, the Earthbender, hid her ability from her family. After the two were kidnapped, Toph managed to fight all the attackers off and joined the group against her parents' wishes. As Earth is the opposite element to Air, Aang went through some difficulties while learning it but eventually got it. On their way to Ba Sing Se, the group found Wan Shi Tong's Library in the middle of the Si Wong Desert and learned valuable information on a solar eclipse that would leave the Firebenders powerless. While sorting through the library's information, they lost Appa, who was taken by desert people and sold. An enraged Aang crossed over into the Avatar State after learning that the Sandbenders muzzled his oldest companion. After finding their way out of the desert and crossing the Serpent's Pass, the group came across a giant Fire Nation Drill which was trying to penetrate the Great Wall of Ba Sing Se. General Sung was reluctant at first to accept the group's help, but after witnessing the quick defeat of his Terra Team at the hands of Ty Lee and Mai, he gladly accepted the Avatar's assistance. In a joint effort, the group managed to fight them off and destroy the drill.
Finally reaching Ba Sing Se, Aang discovered that the city wasn't like he thought; true power didn't lie with the Earth King, but with his adviser, Long Feng, who controlled the secret police, the Dai Li. They figured out where Long Feng had his secret base and infiltrated it, believing that he held Appa captive. After reuniting with Appa, they stormed the palace and managed to tell the Earth King about the solar eclipse and Long Feng's betrayal. After they convinced the Earth King Kuei, his men searched Long Feng's office and thus Aang received a message from Guru Pathik, who had tied it to Appa's horn, telling him to meet him at the Eastern Air Temple so he could teach Aang how to control the Avatar State. While there, Pathik helped Aang open all his Chakras but one, the Thought Chakra. Aang struggled with this one when he learned he had to let go of his feelings for Katara. He told the Guru that he would try, but during his attempt, he had a vision about her being in danger and immediately returned to the city, blocking his chakra. On the way back, he picked up Sokka and Toph and together they learned that Azula and her friends had infiltrated the city. After Aang freed Katara, they both fought Zuko and Azula in the Crystal Catacombs. Things took a turn for the worse when the Dai Li, now under Azula's command, arrived. Aang retreated and tried to use the Avatar State but was struck down in the back by lightning from Azula. The very powerful lightning bolt shot through his body, exiting through his left foot, making his seventh chakra impossible to re-open. The lightning bolt killed him while he was in the Avatar State, severing the connection of the Avatar Spirit to the Avatar World and causing the Avatar to fall from the plane of existence. Katara caught Aang while he plummeted to the ground. A surprising intervention of Iroh allowed her to bring Aang to safety. Aang's lifeless body lay on Appa's back, where Katara used water from the Spirit Oasis in the North Pole to claim back his life, which revived the Avatar Spirit in turn, but his ability to use the Avatar State was now inaccessible.
Book 3: Fire Edit
- Main article: History of Aang (Summer 100 ASC)
At the peak of his potential, Aang simultaneously bends the elements of the Avatar world.Added by The 888th Avatar For several weeks, Aang was unconscious as he recovered from his injury. Mentally, he spent this time in the Spirit World, where he reconnected with his four previous selves to heal the Avatar Spirit. However, upon his awakening, Aang had no memory of his long journey through the Spirit World and his meetings with his former lives. Aang woke up to find himself aboard a Fire Nation vessel, believing that he had been captured. Upon realizing that he had fallen at Ba Sing Se and thus failed, he fled the ship and washed up on Crescent Island where his friends caught up with him again. Team Avatar then reached the Fire Nation and prepared for the invasion, planned during the Day of Black Sun. In the meantime, he was threatened by Combustion Man, an assassin Zuko sent after him. On the day of the eclipse, Aang, Sokka, and Toph went looking for Fire Lord Ozai, but Azula distracted them long enough for the eclipse to end. They decided to retreat to fight another day.
Afterward, Team Avatar and a few others went to the Western Air Temple, where Zuko appeared and wanted to join their group. Initially they rejected him, but when Zuko helped them defeat Combustion Man, Aang accepted him as his Firebending teacher. When Zuko lost touch with his inner fire, Zuko and Aang sought out the Sun Warriors to learn the original source of Firebending and underwent a trial from the dragons Ran and Shaw that increased both Firebenders' abilities.
Due to his belief in the sacredness of all life, Aang felt strong anxiety about the concept of killing Ozai. When he left for an island off the shore of Ember Island, he met the Lion Turtle who taught him about Energybending. Armed with this knowledge, Aang went on to defeat the Fire Lord by taking away his Firebending. He vowed at Fire Lord Zuko's coronation to help him restore peace to the world. After Zuko's coronation, Aang is seen in Ba Sing Se with his friends, where he and Katara began a romantic relationship with a passionate kiss.
After the War Edit
A massive statue of Aang above the Republic City.Added by The Bos After the War, Aang managed to maintain a period of peace. Together with his friend and the new Fire Lord, Zuko, he built the United Republic territory, where a metropolis named Republic City is home to people from all nations gathered to live together. Aang also found an island filled with lost Flying Bison, along with a new type of Winged-Lemur, the Ring-Tailed Winged-Lemur.
Some time during this period, Aang married Katara and the two had three children, the youngest of which, Tenzin, was the only Airbender. Tenzin later went on and married Pema, and the two gave Aang three grandchildren: Jinora, Ikki, and Meelo; however, Aang did not meet them before his death.
Fifty-three years after the end of the War, Aang passed away. His seemingly early death was the result of a long-term side-effect due to the one hundred years he spent frozen in the iceberg while in the Avatar State. Aang was then reincarnated into the Southern Water Tribe as a girl named Korra. It is currently unknown whether or not he will appear in the Spirit World to act as a mentor to Korra, but the possibility still stands and is very likely.
Aang was fun-loving, somewhat naive, and adventurous. He possessed a deep respect for life and freedom, refused to eat meat, and was often reluctant to fight. He craved the stimulation of new people and places. His frequent off-course detours frustrated both allies and pursuers alike. Yet Aang had always prided himself on a complex social network of friends extending over all four nations, and war did not stand in his way. In addition, he looked forward to playing with all the exotic fauna in each place he visited. Whether it was otter penguins, hopping llamas, hog monkeys, or giant koi fish, no fit animal Aang saw went un-ridden.
Within this carefree exterior, however, Aang hid a great deal of guilt and mental burden in his duties as Avatar. Very much the reluctant hero, he wished he had been there to help his people a century ago. This initially caused him to conceal his true identity from friends, and he still had a tendency to slack off in his studies of the Bending Arts, even though he naturally excelled at it. He also tended to become very distressed when he saw destruction caused by the war, believing that as the Avatar, it was his job to prevent such events from happening. Eventually, Aang decided to stop dwelling on the past; however, on several occasions his desire to end the war caused him to take desperate action such as attempting to induce the Avatar State or facing Fire Lord Ozai before he had fully mastered the elements.
As a natural pacifist, Aang chooses to employ frustration rather than violence against Azula.Added by Thailog Being the last Airbender and having no living peers, with the exception of the aged King Bumi and Guru Pathik, Aang had developed very strong bonds with his friends, particularly Katara, explained by Guru Pathik as a reincarnation of his love for his people. His desire to protect them, however, lead to violent emotional outbursts when they were threatened, and he would even resort to deceiving and hurting others to keep the group together. Aang heard that Katara and Sokka might leave the group to visit their father, so Aang hid the map showing his whereabouts and lied about ever having it in the first place. 
Aang preferred not to use his bending skill in battle due to his peaceful nature. He preferred to solve problems non-violently. Even when forced into combat, Aang typically held back, fighting defensively and trying to subdue opponents without seriously hurting them, even if they were not human. This attitude was apparently common among all Airbenders, who were all vegetarians and taught that all living things are precious. The only exception to Aang's pacifism was when his friends were threatened; in which case, he got very angry and relentlessly attacked his opponents, sometimes even entering the Avatar State.
Events in the Earth Kingdom, however, began to take a toll on his care-free personality. Aang's attitude changed dramatically when Appa was captured. He became visibly enraged and hostile, particularly toward Toph, who was "keeping an eye on" Appa while they were gone. Despite attempts by Katara to calm Aang down, his anger continued to grow until finally he flew off to search for Appa alone. Eventually Aang returned to the group, but he was still visibly upset. He violated the principles of Airbending when Momo was snatched up by a Buzzard-Wasp. He gave chase and rescued Momo, but then unnecessarily struck it down with powerful Airbending, decapitating the animal in all his fury. After Aang returned with Momo, the group was confronted by the Sandbenders who had taken Appa. When one of the benders revealed that they had sold the bison, Aang lashed out and smashed all their sand-sailors in a matter of moments using his Airbending. He then turned his sights on the Sandbenders and entered the Avatar State upon hearing that Ghashiun had put a muzzle on Appa. Aang's rage was only stopped when Katara grabbed hold of him and held him in an embrace until he finally calmed down and returned to his normal state. Shortly after these events, Aang forsook all hope, choosing not to care at all in order to refrain from lashing out in anger and be hurt. The birth of baby Hope lifted his spirits once again.
Enraged at the loss of Appa, the Avatar state is triggered through uncontrollable fury.Added by Thailog After failing in Ba Sing Se, Aang began to feel angry and upset with himself. He felt an urge to redeem himself and refused to let the others fight and be injured in the invasion due to "his mistake." After leaving the ship in a violent storm, he was stopped in the water by the harsh tides, but the spirits of Yue and Roku allowed Aang to see that his mistakes were not his fault and to let others help him. He returned to his lighter attitude soon after.
Four days before the invasion, Aang began to have nightmares about fighting against the Fire Lord. After each dream, Aang started to unravel and chose to avoid them by not sleeping. This caused him to mentally fall apart even more, causing Aang to see intense hallucinations, blanking off into realistic daydreams. On the night before the invasion, his friends finally forced him to sleep, during which he defeated the Fire Lord in his dreams and came back to sanity. 
During the invasion, Aang became extremely upset upon not being able to find Fire Lord Ozai, believing that he had lost his only chance to defeat him and end the war. Aang later decided to face Ozai anyway, even though at this time the eclipse had passed and Ozai now had his powerful Firebending back. He was dissuaded, however, by Toph and Sokka, who advised him to retreat and attack at a more advantageous time. 
Aang eventually accepts his duty to master Firebending, accepting Zuko into the group.Added by Thailog After the invasion, Aang was unwilling to face the reality of having to learn Firebending and wanted to have some fun at the Western Air Temple; however, with the arrival of Zuko, he once again began training in earnest. Although he had planned to wait until after the comet to face Ozai, upon learning of the Fire Lord's plan to burn through the Earth Kingdom, he decided to engage him anyway, even though he wasn't fully trained. He also became extremely conflicted upon learning that he would probably have to take Ozai's life.
- Main article: Bending Arts
As the current reincarnation of the spiritual entity known as the Avatar Spirit, the spirit of the world in human form, Aang possessed the power to bend all four elements, making him the strongest and most powerful bender in the world. Because the Avatar Spirit had mastered all the elements many lifetimes over, Aang had exceptional natural talent towards bending. Aang could also bend more than two elements at the same time. Though Avatar Roku said mastering the elements could take many years, Aang was able to learn all four within a year, though technically he did not completely master all four as stated by Zuko and Toph. Most Avatars were not told of their status until they were sixteen years of age, but Aang had become a fully-realized Avatar by the end of the series, while he was biologically still only twelve years old, making him the youngest known person to do so. Conversely, because he was chronologically one hundred and twelve years old, Aang also had the distinction of having taken the longest to achieve this status. Aang never demonstrated the special sub-sets of each Bending Art (such as healing, generating lightning, Bloodbending or Metalbending), however it is possible he learned these skills later, as his training was unconventional.
- Main article: Airbending
Aang is the sole, living Airbending master of the series.Added by Renatabls By the series' beginning, Aang was already an Airbending master, the youngest in history. Aang achieved his mastery tattoos when he mastered thirty-five of the thirty-six tiers of Airbending and invented a new Airbending technique, the "Air Scooter". Because air was his native element, it was the one he utilized the most in battle. Once Aang began to learn the other elements, for tactical purposes he relied less on Airbending, though it continued to remain his signature element. As a master, Aang's skill with Airbending was exceptional, being able to fight on-par with strong and powerful masters or against large numbers of opponents. He had been shown to create tornadoes and currents of air strong enough to lift or deflect extremely heavy objects. Aang's skill with air was great, even perilous, though his pacifistic Air Nomad nature halted the use of air as a deadly weapon (unless he was enraged or in the Avatar State). Instead, Aang used Airbending for pure defense, evasion or other round-about methods of combat other than aggression. When not in battle, Aang used Airbending in his everyday life, often for flying with his glider, or simply to augment his natural agility. While in the Avatar State, Aang's Airbending power was magnified to the point he could erode solid rock away with a powerful gust of air.
- Main article: Waterbending
Aang "has the reflexes of a Waterbending master".Added by Renatabls Although Aang was originally better at Waterbending than his fourteen-year-old friend Katara, she was deemed a Waterbending master after rapidly developing her skills while training under Master Pakku. Katara became Aang's teacher when they took their leave of the North Pole. Aang had great skill with Waterbending, though it was one of his least used elements in battle, instead favoring other readily-available elements such as earth or air. He did not carry a water skin, preferring to bend from large sources of water such as rivers, lakes, or oceans. It was clear Aang had complete and total mastery over the element, capable of creating massive tidal waves (with the help of the moon spirit) or bending entire streams of water. He was even able to extinquish a powerful blast of fire from Ozai, then used the water to briefly put the Fire Lord on the defensive. While in the Avatar State, Aang could bend an entire ocean to rise, mimicking the moon pulling the tides. Unlike Katara, Aang did not learn the healing aspects of Waterbending.
- Main article: Earthbending
Aang tends to utilize the defensive tactics of Earthbending, as it is his nature.Added by Thailog Because Earthbending was the natural opposing art of Airbending, Aang had great difficulty learning the bending art. Airbenders relied on indirect methods of combat, while Earthbending required a head-on approach. When Aang was forced to protect Sokka from a Saber-tooth Moose-Lion, he eventually stood his ground rather than avoid conflict, showing that he had an Earthbender's attitude; he was able to Earthbend soon thereafter. His Earthbending improved greatly, allowing him to utilize Air, Water and Earthbending in combat together effectively. Earthbending had even become Aang's second most used fighting style behind Airbending, due to its general availability. Aang was capable of bending large boulders, sending massive columns of rock flying, or forming earthen armor around his body for protection. Aang eventually learned to fight and bend blindfolded, detecting things outside of his line of vision by using Toph's seismic sense. While in the Avatar State, Aang could manipulate massive columns of rock, compress boulders into pebbles, or send rocks flying at mach speeds, and required no physical connection with the ground to Earthbend. Aang did not learn to bend metal, expressing interest in doing so only sarcastically while sabotaging the drill at Ba Sing Se before the technique was developed by Toph. Despite the proficiency with which Aang used Earthbending in his fight with Ozai, Toph had expressed an opinion that he could still improve; however, it was unclear if she felt he had not yet mastered it or that he could simply improve a bit more.
- Main article: Firebending
Aang finally accepts and utilizes Firebending as he learns the true functioning of it from the Sun Warriors.Added by Renatabls Aang was given the opportunity to learn Firebending early from Master Jeong Jeong, against the normal order of learning (Air, Water, Earth, Fire). While training, Aang's impatience to learn the basics of Firebending resulted in him harming Katara, an accident which caused him great shame. He swore from then on never to Firebend again, out of fear of losing control again. It wasn't until after the Invasion plan failed that Aang sought to learn Firebending again. After accepting Prince Zuko as his teacher and discovering the true meaning of Firebending from the dragons Ran and Shaw, Aang no longer feared Firebending and began his training in the bending art. He was shown to be quite skilled, yet initially reluctant to show the aggressive attitude required for Firebending. Aang was capable of the ancient Dancing Dragon form, as well as highly strong and powerful kicks and blasts able to incapacitate a Fire Nation Airship with the help of Sozin's Comet which had greatly strengthened and enhanced his Firebending abilities to numerous power levels at the time. In preparation for his face off with Fire Lord Ozai, Zuko taught Aang lightning redirection, a highly advanced and unique technique of Firebending that Zuko's paternal uncle Iroh invented by observing Waterbenders. While in the Avatar State, Aang could create exceedingly strong and highly destructive streams of fire, as well as melt solid stone. Aang did not learn to generate lightning during the series.
- Main article: Energybending
Rather than committing homicide, Aang strips Ozai of his destructive power by employing Energybending.Added by The Bos Aang was also able to use a very unique and ancient form of bending called Energybending, which he used to strip Ozai of his natural Firebending abilities, leaving Ozai permanently drained and in a state of weakness. According to the Lion Turtle, before the Avatar existed, people did not bend the four elements, but the life force energy within themselves. However, in order to bend another's life force energy, the Energybender's own life energy must be unbendable, or they could become corrupted or even destroyed. It had been confirmed that Aang was not the first Avatar to learn Energybending; however, there were very few who have learned this particular bending art and even fewer who have used it due to its dangers. The full range and potential of Energybending was not shown. It might be possible (since Energybending can permanently remove a bender's innate bending powers) for Energybending to permanently grant people bending powers and abilities as well.
Other Skills Edit
Aang demonstrates his elusive abilities in his spar with Hide.Added by Thailog Aang was extremely agile and quick even without bending. He was able to defend himself without needing to resort to bending by simply dodging and avoiding attacks. He sometimes used techniques similar to the martial art Aikido, which was the pursuit of harmony in conflict situations, rather than destroying or defeating the opponent. This technique was shown in Aang's fight against the student Hide in the Fire Nation School. Aang defeated him without even touching him, instead simply dodging his blows and pushing him when he was off-balance.
This behavior was matched by his Airbending principles, which emphasized non-aggression. The martial art which Airbending is based on, Baguazhang, consists of intricate foot and palm movements to dodge, walk circles around the enemy and strike unexpectedly as well as defend from all angles - all principles which Aang utilized often.
Aang could use his glider staff with great skill as well, using it sometimes for attack, defense, or bending.
Aang was also an agile and extremely talented dancer, being able to perform somersaults in mid-air among other acrobatic feats and coordinate with Katara in a dance. His somersaults at that time did not seem to be aided by Airbending, as he was in a public area surrounded by Fire Nation students and there was no sign of any air currents around him. He was also able to play the Tsungi Horn, although he was self-admittedly terrible at it.
Avatar Spirit Edit
Aang was a reincarnation of the spiritual entity of the planet known as the Avatar, which has been continually reincarnated since before memorable history. The passage of reincarnation moves from the population of the Air Nomads to the Water Tribes, Earth Kingdom and Fire Nation in order. The most recent incarnations were Avatar Roku (fire), Avatar Kyoshi (earth), Avatar Kuruk (water) and Avatar Yangchen (air). Aang often received advice and guidance from Avatar Roku, the previous Avatar incarnation. Born into the Fire Nation in life, Roku was a benign force in spirit, serving as Aang's adviser and protector. On the Winter Solstice, after informing Aang of the impending return of Sozin's Comet, he manifested himself to defeat a group of Firebenders holding Aang's friends hostage. (When Roku manifested, his voice could be heard behind Aang's when he spoke.) He had guided Aang several times since, appearing to Jeong Jeong to persuade him to teach Aang, offering critical wisdom in the ways of the Spirit World, and revealing to Aang the nature of the Avatar State.
Aang begins to understand the dynamics of the Avatar Spirit.Added by Renatabls After receiving a letter from Guru Pathik, Aang journeyed to the Eastern Air Temple to learn to control the Avatar State. Guru Pathik revealed that the secret of entering, controlling, and leaving the Avatar State by free will laid in the 'releasing' of seven chakras. Aang had little trouble with the first six, but struggled with the seventh - earthly attachments, mainly being Aang's attachment to Katara. Aang's love for Katara, accompanied by a vivid distant vision of her in dire need of help, captured in Ba Sing Se, caused him to leave the Guru and return to Ba Sing Se. Guru Pathik stated that Aang's refusal to let Katara go had 'locked the final chakra' and disallowed him to enter the Avatar State at all. Later, however, Aang began to open the seventh and final chakra successfully and entered the Avatar State by doing just as he had been told - letting go of his feelings for Katara. However, moments after entering the Avatar State, the process was suddenly interrupted as he was struck with lightning from behind by Azula, killing him and removing him from the Avatar State, and the Avatar Spirit itself from the plane of existence. Fortunately, after their escape, Katara was able to use the special water from the Spirit Oasis to revive him.
Nonetheless, Aang's connection to his previous lives was severely damaged by this and he had to undertake a journey into the Spirit World, meeting with the last four Avatars to revive and heal the Avatar Spirit. While he succeeded in healing the Avatar Spirit, the link to his past selves was not completely restored because of his still injured physical body, rendering him unable to enter the Avatar State. He, however, was still able to contact his past lives and enter the Spirit World. It was only when Ozai violently shoved him against a pointy rock that the connection was fully restored.
The Avatar also had the capacity to act as a medium, a bridge between mortal world and the Spirit World, the plane of existence where the universe's disembodied spirits dwell. Through inducing a deep meditative state, Aang could separate from his body and travel the physical world's astral plane in astral form or, with the help of a gateway, travel completely to the Spirit World. Once in the Spirit World, Aang could travel freely and communicate with beings such as Avatar Roku or Koh the Face Stealer. This position as intermediary also allowed him to channel other spirits while in the Avatar State. He once acted as the Avatar of the Ocean Spirit to defeat the Fire Nation during the siege of the North Pole. He had also channeled the spirits of previous Avatars, namely Roku and Kyoshi.