Chi (Earth-8138)

Chi is a metaphysical energy that surrounds all humans on Earth, serving as a concept for the root of all bending and techniques. Most commonly used in hand seals, chi can be manipulated to bend the elements of nature: water, earth, fire, and air, as well as to create specialized sub-effects that would otherwise be impossible, including walking on water and creating illusions. Chi itself is seen as a bright blue energy, although it is invisible to the naked eye unless it is highly concentrated or manifested.

Chi blocking
Chi blocking is a special technique for those possessing unparalleled knowledge of the human body, allowing them to block one's chi paths and weak points. One such individual, Ty Lee, could use chi blocking to disable her opponent's ability to bend and perform a jutsu. This art was used by the Hidden Sound Village's Equalists, who used to method to counteract bending.

Tailed Beast chi
The tailed beasts are the nine colossal monsters that are the living form of chi, created by the fabled Sage of Six Paths from the chi of Vaatu. Each beast is unique in appearance and have a different number of tails, from one to nine. Their chi is unique, and is colored red.