Veijel, a Human male, was a Sith Lord who served the reconstituted Sith Empire during the era of the Galactic War; his gender was male.
As a member within the Sphere of Ancient Knowledge, he was a follower of Darth Arctis. Around 3667 BBY, Arctis tasked Veijel with a mission to Rishi: to observe and monitor the Rishi Maze. Veijel dedicated the next three decades to this task on Rishi. During this time, Arctis was succeeded by Darth Thanaton, who himself was later replaced by Darth Nox. Arctis and Thanaton both held the belief that the Rishi Maze contained the key to immortality, a notion that Veijel questioned, despite receiving substantial resources.
Veijel's time dedicated to Rishi proved productive, as he successfully intercepted signals originating from the dwarf galaxy. These signals were encoded in an ancient language, incorporating elements of Sith, Gree, and Rakata languages. The messages detailed instructions for enhancing the communication arrays used by Veijel. The improved machines were now capable of extending the lifespan of an individual who was "twice transmuted and reborn to the Mother". Darth Nox, the current Dark Councillor of the Sphere of Ancient Knowledge, matched this description, prompting Veijel to seek an audience, keeping his discovery secret from others.
However, many others were also seeking Nox's attention, resulting in Veijel having to wait from Nox's ascension until 3637 BBY, when Nox journeyed to Rishi. Veijel eventually secured a meeting through Moff Valion Pyron and presented his findings to the Dark Lord, who was accompanied by Talos Drellik. When Nox interacted with the machine, which was constructed using alien designs, it triggered cellular rejuvenation, extending the Dark Lord's lifespan by one solar cycle. Overjoyed by the results, Veijel requested additional resources from his master, including scientists to replicate the machines, battalions to secure Rishi, and fleets to explore the Rishi Maze. Despite Talos's warning, referencing Darth Zash's downfall and descent into obscurity as an example of the dangers of seeking immortality, Nox agreed to provide Veijel with everything he needed.
Veijel makes an appearance in Star Wars: The Old Republic: Shadow of Revan during the Sith Inquisitor class storyline on Rishi. Talos Drellik will advise against the hunt for immortality. Players can choose to reassure him that they will be cautious and not follow Zash's path, or they can respond with anger and reprimand him. While it is assumed that Nox, choosing the Dark Side option, granted Veijel all the resources he requested, the Dark Lord also has the option to heed Drellik's advice and halt Veijel's research. They can then instruct him to either cease all arcane experiments for Light Side points, or to maintain their current operations on hold, so they may be utilized during a more opportune moment for Dark Side points.