Energy bending is the ability to bend another person’s life energy. It predates the four main bending arts, the formation of the four nations, as well as the creation of the Avatar.
Before the Avatar came into existence and the separation of the four nations, the lion turtles bent the energy within humans and themselves in order to grant them the ability to bend one of the four elements. However, after the lion turtles denounced their roles as protectors of mankind, energy bending was no longer used to grant people bending, and the knowledge of energy bending was almost completely lost
The capabilities of energy bending are not well understood; what is known is that bending a person’s life energy can impart them with knowledge instantly, remove their bending completely, or restore it. This bending art can be perilous to the user, which is why so few have ever used it. In addition, even though mastering the four elements is a necessity for the Avatar, learning energy bending is optional.
Energy bending is an extremely powerful and potentially dangerous technique. If the bender’s spirit is even slightly weak, or bendable, they will be infected by the spirit of the one they are bending. As a result, the bender can be corrupted and even destroyed.