Irek Ismaren (3 BBY – 27 ABY) is a character in the Star Wars Expanded Universe. He apparently was the son of Roganda Ismaren and Sarcev Quest, but Irek's father was often rumored to be none other than Emperor Palpatine himself.
Irek and his mother managed to somehow book passage off the planet and relocated to an unnamed location in the Corva Sector, and later to Coruscant, where Roganda had more alterations done to her son, including upgrading the memory chip in his brain, forcing his body to grow well past maturity so he reached a height of three meters, and having lightsabers implanted in his knees, wrists, and elbows.
Roganda hired a Dark Jedi to teach Irek further in the dark side of the Force, but after Irek got mad at the Dark Jedi, he killed him, but not before the Dark Jedi put a lightsaber through Irek's brain.
A second series of experiments were begun to try and save Irek from brain death. Before the process was complete, Irek broke free and killed his mother. Because he could not speak and had no idea who he was or what had happened to him, it was at this point he took the name 'Lord Nyax' from the Corellian legend, after hearing it in the minds of his victims, and terrorized the stranded citizens of Coruscant after the planet fell to the control of the Yuuzhan Vong. Nyax used mind control on the survivors of Coruscant's fall to get them scout out the Yuuzhan Vong for him, as well as for other tasks such as clearing paths and the like.
From a large 'knot' he sensed in the Force, Nyax had discovered the location of the old Jedi Temple, and used the Force wellspring underneath it to become even more powerful. Luke Skywalker, Mara Jade Skywalker, and Tahiri Veila, who were on Coruscant as part of a reconnaissance team, discovered Nyax and fought him. Since battling Nyax with lightsabers was out of the question, the three used the Force and assaulted him with rubble. Tapping into the Yuuzhan Vong part of her personality Tahiri made herself invisible to Lord Nyax's force senses and crippled him with rocks she shot at him with the Force. Nyax fell into a nearby pit near the Force wellspring, drew all the dark side energy he could muster, and released it, devastating the surrounding area. His body had died, but his dark side presence lingered on in nearby structures.