Nico Diath

Born as a Human male, Nico Diath came from a family distinguished by its legacy of producing numerous Jedi Masters. He was a descendant of the ancient Jedi Masters Sidrona and Dace Diath, both of whom participated in the Great Sith War. During the closing decades of the Galactic Republic, the Jedi Order provided him with training in the Force, leading to his eventual attainment of the Jedi Master rank. Throughout his time within the Order, Diath mentored his nephew Tae as his Padawan. To help Tae control his telepathic abilities, Diath would have his nephew focus on his own thoughts whenever Tae struggled. Diath rarely made visits to the Jedi Temple on the galactic capital Coruscant. Instead, he spent much of his time traveling across the Outer Rim Territories, where he freed more than one thousand slaves, earning the animosity of their Hutt slave owners. By the onset of the Clone Wars, a conflict between the Galactic Republic and the Confederacy of Independent Systems, Diath was celebrated as a legend within the Jedi Order.

Four months into the Clone Wars, Diath journeyed to the planet of Queyta, where he joined Jedi Masters Jon Antilles, Fay, and Knol Ven'nari to acquire a sample of the antidote for the Separatist chemical weapon known as swamp gas. The Separatists had successfully tested the airborne gas against the Gungan colony on Ohma-D'un, a moon of the planet Naboo. Diath was placed in command of the team, which was soon joined by Jedi Knight Obi-Wan Kenobi. Upon his arrival, Diath and his fellow Jedi successfully infiltrated the mobile Separatist facility, situated on a small island that moved along one of the planet's lava streams.

Upon entering the facility, Diath and Ven'nari observed the scarcity of battle droids guarding the base. As Ven'nari prepared to engage the guards, Antilles pointed out that they were Skakoans—a species that breathed methane and had to wear pressurized armor—and that attacking them with a lightsaber would cause them to explode. Diath realized that the team would need to avoid the Skakoan sentries. Kenobi examined the facility's schematics and located the laboratory where the antidote was located. Upon reaching the laboratory, Diath and the Jedi encountered the Dark Jedi Asajj Ventress and the Gen'Dai bounty hunter Durge, who were allied with the Confederacy. They informed Diath and his group that their spies had already alerted them to the Jedi's presence in the facility. When Durge shot two of the Skakoans, causing them to explode, Ven'nari used her pyrokinetic Force abilities to draw the fire toward herself. After the fire dissipated, Diath and the team found Ven'nari suffering from severe burns. He used the Force to comfort Ven'nari as she died.

As the facility began to sink into the lava stream due to Durge's explosion, the four surviving Jedi pursued Ventress, who possessed the antidote. However, both the Dark Jedi and the bounty hunter caused the facility's ceiling to collapse. Some lava struck Diath as he stood on a catwalk, burning the Jedi Master and causing him to fall into the lava stream. Before Diath was incinerated, he urged Antilles, Fay, and Kenobi to escape the facility.

Following Diath's death, Antilles and Fay were killed by Durge and Ventress, respectively. Although Kenobi was the only survivor, he managed to secure the antidote and return to the Jedi Temple on Coruscant. After Kenobi recovered from his injuries, a holographic memorial service was held to honor Diath and the other three Jedi Masters. During a Republic campaign on the planet Jabiim, Tae Diath came to believe that his uncle was stronger and more powerful than he and his fellow Padawans combined. Yet, due to Diath's death, Tae was losing control of his telepathy. Tae was killed during the conflict on Jabiim.

Nico Diath, a Human male, typically wore brown Jedi robes and carried a lightsaber with a blue crystal. He was known as one of the Jedi Order's nomads, rarely visiting the Jedi Temple on Coruscant. Nevertheless, Diath remained committed to fighting for peace and freedom in the galaxy. During the mission to Queyta, Diath emphasized the importance of their mission, despite the risks involved. As Knol Ven'nari was dying, he took the time to alleviate her suffering. After her death, he was determined to pursue the Dark Jedi Asajj Ventress. Before his own death, he ordered Jon Antilles, Fay, and Obi-Wan Kenobi to flee from the facility.

Diath inherited the Force-sensitivity passed down through his family's bloodline, eventually achieving the rank of Jedi Master. When he trained his nephew Tae—who possessed telepathic abilities—Diath encouraged Tae to focus on his own thoughts whenever his nephew struggled to control his telepathy. During the mission to Queyta, Diath demonstrated his proficiency with Force flight, using it to infiltrate the Separatist facility.

Nico Diath was created by W. Haden Blackman for the standalone comic Blast Radius, which was the fifty-third issue of the Star Wars: Republic comic series. Brian Ching provided the artwork for the issue. Diath—along with Jon Antilles, Fay, and Knol Ven'nari—received an indirect mention in The New Essential Chronology's account of the mission to Queyta. He was also mentioned in The Official Star Wars Fact File 111, and later received a dedicated entry in The Complete Star Wars Encyclopedia.