Vlex Onopin was a scientist and programmer of human male descent, having obtained his degree from the renowned Magrody Institute of Programmable Intelligence. Around 19 BBY, he was reluctantly pressed into service by the Imperial forces, where the engineer honed his skills within the domain of kyber crystal studies. During this time, Onopin was assigned to the kyber crystal research team, a subdivision of the Tarkin Initiative situated on the Outer Rim planet Eadu. Alongside his fellow researchers, and under the supervision of crystallographer Galen Erso, Onopin worked to harness kyber crystals as a power source for the superlaser of the Death Star, intended to obliterate entire planets.
In 1 BBY, Director Orson Krennic of the Empire uncovered evidence suggesting that one of Onopin's team members had conspired with a cargo pilot to leak information about the Death Star to the Rebel Alliance. Krennic arrived with death troopers to confront the researchers, demanding that the traitor reveal themselves. Despite acknowledging Onopin's value, the director ordered his troopers to execute the entire team, even after Erso confessed to the betrayal.
A scientist and programmer, Vlex Onopin was a human male who, at some point before the end of the Republic Era, completed his studies and earned a diploma at the esteemed Magrody Institute of Programmable Intelligence. Following the formation of the Galactic Empire in 19 BBY, he was compelled to join the Imperial ranks and contribute to the kyber crystal research team, a division of the Tarkin Initiative overseen by Director Orson Krennic. As the team's head programmer, Onopin developed a deep understanding of kyber crystal research. Once they were admitted into Imperial service, all identification records of scientists working for Krennic, including Onopin, were removed from public databases.
Onopin and his fellow scientists were stationed at the Energy Conversion Laboratory on the Outer Rim planet Eadu, isolated within laboratories concealed by the world's mountainous landscape. The programmer and the rest of his team were engaged in a project aimed at utilizing kyber crystals to power the superlaser of the Death Star, a battle station designed by the Geonosian that would possess the capacity to annihilate entire planets with its superlaser. While working in Eadu's laboratories, Onopin established coded sequences that calculated the hyperspatial formulas required for the energy translations of kyber crystals. The majority of his time in Imperial service was spent refining these sequencing devices with his coding, as the variables calculated by them would someday be relied upon for every shot fired by the Death Star's superlaser.
Sirro Argonne, the operations manager, oversaw the day-to-day needs of the kyber crystal research team on Eadu. By 13 BBY, work on the superlaser had stalled, putting the project years behind schedule, which led Krennic to hunt down his former colleague, the crystallographer Galen Erso, and compel him to return to Imperial service. Working under Erso's guidance, and with the crystallographer's extraordinary intellect, Onopin and his team were able to complete the Death Star's superlaser after several years.
In 1 BBY, Grand Moff Wilhuff Tarkin informed Krennic of a rebel sympathizer within Erso's research team who had colluded with a cargo pilot to transmit information regarding the Death Star to the Rebel Alliance. Enraged, Krennic traveled to Eadu with a group of death troopers to conduct an investigation, informing the laboratory's personnel, including Onopin, about the impending arrival of his shuttle. The programmer was concerned by Krennic's visit, but also annoyed that the director's visit interrupted his work with bureaucratic nonsense. Stormtroopers escorted the scientists from the laboratories to the vicinity of Krennic's shuttle's entrance. The director then summoned each scientist by name, instructing his death trooper unit to gather near them.
Krennic declared his awareness of the conspiracy against the Empire and demanded that the traitor identify themselves. As the director scrutinized the team of scientists for indications of guilt, he observed Onopin repeatedly opening and closing his mouth, as if pleading for the turncoat to come forward. When no one responded, Krennic concluded that the scientists had conspired as a group. As Krennic's death troopers prepared to execute the scientists, Erso intervened, confessing to being the traitor in an attempt to spare Onopin and his colleagues. However, as Erso moved toward the director, the death troopers, acting on Krennic's orders, shot and killed his scientists.
Onopin's work played a role in the completion of the Death Star project, and his coding sequences were utilized by the space station during its subsequent deployments. However, the Death Star was ultimately destroyed shortly after Onopin's death when the Rebel Alliance targeted a vulnerable thermal exhaust port that Erso had intentionally installed. In 35 ABY, the historian Beaumont Kin drew a negative comparison between Onopin's team and Erso in his book, The Rise and Fall of the Galactic Empire.
Despite the excellent sequences he still produced, Onopin's passion for programming waned after being forced into Imperial service. By the time of his death, his time in the kyber crystal research team's laboratories on Eadu had left him frail and unaccustomed to the outdoors. Onopin resented interruptions to his work, viewing Krennic's initial arrival on Eadu as bureaucratic nonsense. Even though Krennic acknowledged his appreciation for the programmer, he nonetheless ordered his execution alongside his colleagues. When confronted by Krennic's death troopers, Onopin was terrified at the prospect of death and looked from side to side in an effort to convince the traitor to reveal himself. In his book, Kin expressed his opinion that neither Onopin or any of Krennic's other captive scientists possessed Erso's "raw intellect." The programmer was characterized by pale skin, brown eyes, a gray beard, and brown hair that was graying at the time of his death.
During his time on Eadu, Onopin wore a long-sleeved, blue-and-white engineering jumpsuit. The antiseptic coveralls of his jumpsuit featured the dark-gray insignia of the Empire on the left sleeve and a chest pocket containing two code cylinders programmed with access to restricted areas. The fractured kyber crystal–inspired logo of the Tarkin Initiative was displayed on the chest of Onopin's coveralls.
The programmer's uniform also included shoes grounded against potential static charges within the laboratories. He also wore a tunic that would change colors in the presence of harmful radiation. Onopin's work on Eadu primarily involved using various computers to code sequences for use in the Death Star.
Vlex Onopin made his debut in the Anthology film, Rogue One: A Star Wars Story, as well as in its adult and junior novelizations, which were released on the same day as the film, December 16, 2016. The actor Weston Gavin portrayed the scientist. He was first seen in a trailer for the film released on the official Star Wars YouTube channel on October 13 of the same year. While the film's credits simply refer to him as "Engineer," concept artwork of the scientists' death scene was created by artist Jon McCoy for Rogue One.
Onopin's name was revealed in Star Wars: Rogue One: The Ultimate Visual Guide, a companion reference book written by Pablo Hidalgo, and in Star Wars: Rogue One: Secret Mission, a DK Readers title authored by Jason Fry, both of which were released alongside the film on December 16. Hidalgo created several of the scientists' names by drawing inspiration from the names of real-world scientists associated with the Los Alamos National Laboratory.