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. Luke Skywalker later used this power to control erratic electrical surges in the Jade's Shadow in order to prevent the ship from being damaged.