Energybending

History
Aang uses spiritbending in the Avatar series' finale "Sozin's Comet." Through the advice from the giant lion-turtle Aang had previously mistook for a island. Spiritbending is the ability to take away someones ability to bend forever, as seen in Sozin's Comet, Part 4: Avatar Aang. In the Avatar world, this can be a fate worse than death, ecspecially for former Fire Lord Ozai, who used to torment and destroy life with his powers.

Benders
So far, only Aang whilst in the controlled Avatar State, is able to use this ability. Though since it is a very old technique, it can be presumed that only the first few Avatars would know of this technique. Also, it can be assumed that one would need to be in the Avatar State whilst in complete control in order to be able to know of the existence of this ability and how to use it.