Hassat-durr was a family of Force techniques used by the Baran Do sages. Translated from the native Kel Dor language into Galactic Basic Standard, it meant "lightning rod". The hassat-durr techniques suffused the user's body with a low level of electromagnetic radiation. Because of this, if the wielder did not have the skills perfected and attempted to use them during a storm, they would be repeatedly struck by lightning. However, when perfected, they allowed the wielder to disable prosthetics and electric implants, interfere with shock shackles, become a range-boosting antenna for a comlink, among other uses.
The ayna-seff—which translated to "dead brain"—technique was in the hassat-durr family. This technique took Jedi Knight Jacen Solo three days to master, while it took Grand Master Luke Skywalker only two. Master of the Order Koro Ziil taught the skill to Solo in 34 ABY—before Solo turned to the dark side and became Darth Caedus—but by the time of Skywalker's arrival on Dorin, Ziil had become the leader of the Hidden Ones, a secret sect of the Baran Do. Tila Mong then became Mistress of the Order, and she taught the ability to Skywalker.