Denolm Orr, a male Human Jedi Master, served as the mentor to Sa'har Kateen. During the Third Galactic War, Orr met his demise on a mission aimed at recovering a holocron from the Temple of Nul. He was slain by the rogue Sith Lord Darth Malgus, who attempted to sway his [Padawan](/article/padawan/legends] against him.
Orr was once part of the Children of the Emperor, a group responsible for various atrocities committed in the Emperor's name. Later, Denolm was freed from the Emperor's influence and joined the Jedi Order. He only disclosed his past to Jedi Master Gnost-Dural, who agreed to keep the information secret. Subsequently, Denolm Orr dedicated himself to eradicating the dark influence of the Children, starting with their creator, Darth Nul.
Prior to the Third Galactic War, Jedi Master Denolm Orr came across two Force-sensitive Twi'lek children. He chose the girl to be his Padawan, while the boy was left behind due to his weaker connection to the Force.
Following Darth Malgus's theft of artifacts from the Great Jedi Library on Ossus and the Jedi Enclave on Dantooine, Task Force Nova discovered that the stolen items originated from the planet Elom and belonged to Darth Nul, a mysterious Sith about whom the Republic had no information.
Denolm Orr assembled a team comprised of Jedi Master Gan Enok, Material Analysis Dr. Mykon Ora, Chief Engineer Rolan Aun, Specialist Tiriz Etto, and his Padawan Sa'har Kateen to find Darth Nul's creations. During their assignment, they encountered Imperial forces. By the time they reached the Temple of Nul, only he and his Padawan remained alive. They approached the device they discovered inside, at which point Darth Malgus appeared and killed the Jedi Master. Before his final breath, he succeeded in destroying the machine, but Malgus still managed to obtain the holocron contained within.