Spirit World



The Spirit World is a parallel plane of reality that co-exists along with the World of Avatar. It is the home of spirits, immortal supernatural entities which often embody different aspects of life and nature. All the past lives of the Avatar exist in the Spirit World.

It is difficult, and therefore rare, for a human to pass into the Spirit World; conversely, only a handful of spirits are able to exist physically in the mortal world, though they must give up their immortality to do so. The Spirit World and the physical world are closest together during the solstices, which makes it possible for spirits to manifest in the mortal world and for humans to pass into the Spirit World. There are also certain locations in the physical world which act as bridges to the Spirit World; these locations are often revered by cultures living near them, such as the Spirit Oasis in the North Pole. The Avatar itself acts as a spiritual bridge between both the worlds and can travel between them freely, though bending has no effect in the Spirit World.

There are few known ways for a mortal to enter into the Spirit World. Probably the most common way is to be carried there by a spirit as the spirit shifts between planes. The Avatar is able to pass fully into the spirit world at times and locations where the barrier separating the two realities is unusually weak, such as at Avatar Temples on a winter solstice or at the Spirit Oasis at the North Pole.

Overview
Very little is known about the Spirit World, in particular its geography. However, in certain places, the Spirit World seems to conform closely to an area of the physical world, to the extent where a mortal making the transition might not immediately take notice of the difference. In other places, such as the North Pole, the geography of the Spirit World seems to have no connection to the physical world, the landscape regions varying considerably.

Koh's realm


The realm of the spirit Koh, the Face Stealer, exists below a gigantic, twisted tree. The land surrounding his lair is barren, dark and scarcely inhabited, except for Koh's faceless victims and at least one gargantuan animal. For anyone who enters his lair it is advisable to remain emotionless, as Koh steals the face of anyone who expresses his or her emotions in front of him.

Solstices
A solstice is an astronomical event that occurs twice a year. During these solstices, the Spirit World and the physical world are significantly closer to each other compared to the rest of the year. Therefore, it is easier to cross over during these solstices. Aang took advantage of the this aspect during the winter solstice to talk to Avatar Roku about Sozin's Comet. Avatar Roku also used the summer solstice sun to help him get into the Avatar State.

The Avatar
The Avatar is the natural bridge between the Spirit World and the physical world. The Avatar can use meditation to enter the Spirit World. When doing so, the spirit of the Avatar leaves his or her physical body, leaving their body defenseless.

Spirit Oasis


The Spirit Oasis is a verdant oasis located in the Northern Water Tribe behind the chief's temple, at the base of a waterfall. It is the center of all the spiritual energy in the entire North Pole and, unlike the rest of the region, has a warmer climate, able to facilitate the growth of vegetation. Two koi fish lie in a central pool of the oasis and are the mortal forms of Tui and La, the Moon and the Ocean spirits, circling each other in eternal dance.

Known spirits

 * Koh, the Face Stealer: He is an ancient, malicious spirit who steals the face of anyone who shows emotion while in his presence. He is extremely knowledgeable, being one of the oldest spirits in existence and possesses the ability to predict future events. Avatar Kuruk holds a grudge against him, constantly hunting after Koh for stealing his loved one, Ummi.
 * Tui and La, the Moon and Ocean Spirits: Near the beginning of the world's creation, the Moon and Ocean Spirits departed for the mortal world and manifested themselves as two koi fish in the sacred Spirit Oasis of the North Pole. Tui and La were the original waterbenders with La being the source and Tui being the originator.
 * Princess Yue, the second Moon Spirit: After Tui was killed by Admiral Zhao, Princess Yue sacrificed her life to become the second Moon spirit, consequently granting her waterbending abilities. Since her father's bargaining with Tui, she has become the reincarnation of the original Moon Spirit.
 * Hei Bai, a Forest Spirit: Typically taking the form of a panda bear, he can manifest himself into a ferocious monster with multiple arms. A spirit of a dense forest near Senlin Village, Hei Bai attacked the village when the Fire Nation destroyed his forest. He later aided Aang along his journey into the Spirit World.
 * Wan Shi Tong, the Knowledge Spirit: Wan Shi Tong brought his immense library of knowledge to the mortal world in the hopes of bettering mankind with wisdom. With the use of fox-like animals known as Knowledge Seekers, he seeks out valuable sources of knowledge, varying from scrolls to ancient tomes. The library was located in the Si Wong Desert until mortals instead used the knowledge to further warfare, prompting Wan Shi Tong to bury the library beneath the sand, thus making the library's discovery impossible. He typically takes the shape of a gigantic black-&-white Barn Owl, but when angered becomes a wyvern-like creature.
 * Painted Lady: She is the spirit of the Jang Hui River, located in the Fire Nation, where villagers worship and build statues of her in her honor. She expressed her gratitude to Katara for fulfilling her duties after she fled the village because of the river's pollution. The Painted Lady has been known to possess healing and spiritual abilities.
 * Odd Monkey Spirit: He is a cranky monkey-like spirit that spends his time meditating. He believes that humans are a waste of time, proven by his treatment of Aang.
 * Avatar Aang: He is an Air Nomad Avatar and the most recent incarnation of the Avatar. He was tasked with the duty of defeating the Fire Lord and restoring balance to the war-stricken world. After his spectacular defeat over Ozai, he began a romantic relationship with his close friend, Katara of the Southern Water Tribe eventually leading to their marriage and culminating with the birth of their son, Tenzin. He later dies of old age, making Korra the new Avatar.
 * Avatar Roku: He is the Fire Nation Avatar that acted as a guide and mentor to Aang throughout his journeys. He was once the best friend of Sozin, however, they became enemies after Sozin began to seek world domination. Sozin left him to die from the poisonous gases from a volcanic eruption. His sparing of Sozin during a conflict in the Earth Kingdom colonies was a major cause of the War. He was a friend of Monk Gyatso, Aang's former guardian and the husband of Ta Min.
 * Avatar Kyoshi: She is an Earth Kingdom Avatar, hailing from Kyoshi Island, and was a tough and "by any means necessary" type of Avatar. She founded the Dai Li to ensure protection of Ba Sing Se's cultural heritage. She has dealt with the likes of the 46th Earth King and Chin the Great, the latter of which she killed.
 * Avatar Kuruk: He is a Water Tribe Avatar from the Northern Water Tribe in constant pursuit of Koh. He was a laid-back and easy-going Avatar that flirted with girls and liked to show off his bending prowess. This would eventually lead to his downfall in life.
 * Avatar Yangchen: She is a female Air Nomad Avatar from the Western Air Temple who advised Aang in the series. A devout Avatar, she was willing to forsake her spiritual customs to ensure peace and safety in the world.
 * Unnamed fire Avatar: An anonymous fire Avatar that was shown erupting volcanoes while in the Avatar State.
 * Fang: Roku's dragon who died along with Roku during the volcano eruption. He can now communicate telepathically with people from the mortal world and give them insight into the Spirit World. As a spirit, Fang is intangible and invisible.

Known visitors

 * Unnamed fire Avatar
 * Avatar Yangchen
 * Avatar Kuruk
 * Avatar Kyoshi
 * Avatar Roku
 * Avatar Aang
 * Ummi, betrothed of Avatar Kuruk
 * Sokka
 * Three villagers from Senlin Village
 * Iroh

Trivia

 * There are no bathrooms in the Spirit World.