Galen, an operative of the Republic Strategic Information Service, was a male Human agent during the time of the Cold War.
During the Cold War era with the Sith Empire, Galen, a male human, became an operative within the Republic Strategic Information Service, which served as the primary intelligence organization for the Galactic Republic. Around the year 3643 BBY, he was stationed on the Republic's capital world of Coruscant, where he oversaw the SIS base located within the Senate Tower. When a group of thieves successfully stole the design schematics for the Planet Prison superweapon, General Var Suthra of the Mon Calamari assigned Galen and his team to spearhead the subsequent investigation. While Galen coordinated his investigative efforts alongside the Coruscant Security Force, the SIS operative maintained leadership over the investigation and reported directly to General Suthra.
Galen's investigation quickly yielded results when his operatives identified one of the thieves from a piece of security footage, a Rodian known as Vistis Garn. Galen immediately informed Suthra, who was in conversation with Jedi Masters Bela Kiwiiks and Orgus Din, Orgus' former Padawan, Kiwiiks' current Padawan Kira Carsen, and Doctor Eli Tarnis, the individual responsible for creating the Planet Prison. Upon learning of Galen's breakthrough, Din instructed his former apprentice—now a Jedi Knight—to collaborate directly with Galen, while the Jedi Masters and Suthra proceeded to confer with Supreme Chancellor Dorian Janarus. Kiwiiks also suggested that Carsen remain, believing her security skills could be valuable. Galen then detailed his lead to the two young Jedi and Doctor Tarnis: Garn, known for his association with the criminal Migrant Merchants' Guild, had recently been observed raiding a military depot for advanced weaponry and munitions.
The Knight, accompanied by the astromech droid T7-O1, ventured into the Guild-controlled Old Galactic Market with the aim of recovering the stolen weapons and design documents, while Galen remained at the Senate Tower, collaborating with Carsen to create diversions within Coruscant's security network, intended to distract the criminals. However, even as the Knight and T7 successfully retrieved the stolen files and weapons, Galen and Carsen discovered a security compromise. Somehow, members of the Black Sun criminal organization had managed to breach the Senate Tower's security measures and abduct Doctor Tarnis right under the noses of the SIS. When the Knight contacted Galen to report their success, the agent tersely instructed the Jedi to return to the Senate Tower to assist in the search for Tarnis. Galen was alarmed to discover that Garn had actually been employed by Black Sun to steal the files in the first place, and passed the recovered files to his subordinate Krand for decryption.
Just as Galen was briefing the Knight on the situation, he received a holocall from Carsen, who, along with CSF forces, had pursued the kidnappers to the nearby spaceport. She and the security team had cornered the kidnappers in Docking Bay 84, but were unable to make further progress. Galen instructed the Knight to assist Carsen, and together the two Jedi managed to defeat the Black Sun operatives and ascertain that Tarnis had been taken to Black Sun territory.
Following the trail of the Black Sun operatives who were believed to have kidnapped Doctor Tarnis, the Jedi Knight uncovered the truth that Tarnis was, in fact, a Sith Lord and the offspring of Darth Angral. This revelation put all of the Republic's superweapon initiatives at risk. Shortly thereafter, Galen departed Coruscant to safeguard the Power Guard Enhancement System on Nar Shaddaa.
Soon after establishing himself on Nar Shaddaa and commencing his assignment, Galen was taken prisoner by the Sith Lord Sadic. Sadic subsequently transformed Galen into a Mark III Power Guard, compelling Galen to obey his directives through the use of extreme pain as punishment for disobedience. In a final act of resistance, Galen turned against Sadic and the other Power Guards. However, they were too strong, and Galen sustained severe injuries. Despite this, Galen survived and, with the assistance of the SIS, learned to control his implants. Utilizing his newfound abilities, Galen went deep undercover within Sith territory. He contacted the Knight who had rescued him and shared the details of his assignment, expressing his gratitude to the Jedi for demonstrating that he still had a purpose in life.
Galen was a capable and committed operative of the SIS. His unwavering dedication was focused on safeguarding the Republic, even at the cost of his own life.
However, his personality underwent a dramatic shift following his transformation into a Power Guard. He became despondent and miserable, not only due to his enslavement to Sadic, but also because of his unwilling transformation. Even after Sadic's demise, he still preferred death over living as a machine, even contemplating suicide. Despite this, he retained some semblance of humanity and loyalty, evident in his assistance to the Hero of Tython in defeating Sadic. When Sadic was defeated, he wanted to stay and die, but when the SIS urged him to come along he obliged.
Subsequently, Galen learned to master his implants and accept his condition. He later sent a message to the Jedi, expressing his gratitude for showing him that he still had something to live for.
Galen makes his initial appearance in Star Wars: The Old Republic as a component of the main narrative quests within the Jedi Knight storyline. At the conclusion of the dark side path, when Galen is a Power Guard cyborg, the Republic player has the option to eliminate him instead of allowing him to live and sacrifice himself.