Subject 1157 was a clone grown from the genetic material of Galen Marek, a Human male serving as the apprentice to the Sith Lord Darth Vader. The Galactic Empire cultivated Subject 1157 within a cloning tank at a cloning facility located on the planet Kamino, starting around 1 BBY. His development was closely observed and documented by a cloning technician through a series of observation logs. Subject 1157 experienced accelerated growth and received genetic memory imprints, leading to the development of consciousness and subsequent "hallucinations" derived from Marek's life. As time progressed, Subject 1157 gained access to the Force, mirroring his genetic template, and demonstrated this power by cracking his tank using Force lightning. Despite frequent sedation following a breach in security, his increasing power rendered the sedation ineffective. During the Battle of Kamino, plans to release Subject 1157 into the training area were thwarted when his tank was struck by a Force push delivered by Subject 1138, resulting in Subject 1157's death.
Galen Marek, a Human male and secret apprentice of the Sith Lord Darth Vader, was the source material for clone Subject 1157. Subject 1157 resided in a cloning tank within the cloning facility on the planet Kamino, starting approximately one year prior to the Battle of Yavin. Like Marek, Subject 1157 was under the influence of the Galactic Empire. During his growth, he was given genetic memory imprints. A cloning technician maintained a record of Subject 1157's progression.
During Phase 13B of his growth, Subject 1157 began exhibiting irregular consciousness, accompanied by shaking. Mindscans were performed to determine the reason for the tremors. By Phase 16D, his vital signs indicated complete motor control, enabling him to resist the stressors caused by genetic impulses and memory imprints. The cloning technician expressed satisfaction with 1157's advancement compared to other subjects and initiated accelerated growth. Following entry 21 in the technician's log, an isolation chamber and PROXY droids were added to a nearby training room in response to Subject 1157's development. The day following entry 25, Darth Vader planned to visit Subject 1157, who had become more stable, and the cloning technician voiced pride in the scientific advancements achieved in the process. By entry 32, 1157 was experiencing "hallucinations" or "memories," which caused him distress. He mastered Force lightning and employed it to damage his tank. Before entry 42, lightning damaged some equipment, forcing medical droids, including a 2-1B droid, to administer treatment manually, leading to inconsistencies in his training. When not sedated, Subject 1157 could use the Force to reach beyond his tank, attacking the droids.
A series of minigames were provided to assess his reflexes, including mazes and pong, with increasing difficulty over time. He was also able to hear sounds from the external environment. During Phase 22A, genetic imprints triggered hallucinations concerning a Human woman, causing anxiety in the clone. In entry 29, the technician noted the anxiety and outlined plans to implement new desensitization techniques. A breach in security—specifically, the escape of another clone—led to the systematic restraint of 1157. Around this period, Darth Vader visited his tank. By Entry 65, the technician suggested that the clone might become an aberration and experimented with alternative sedation methods. Although the restraints weakened the clone, they had no effect on his temperament.
Subject 1157 periodically experienced visions of both Galen Marek's life and the escaped clone. Some visions appeared to depict events happening in real time. The cloning technician frequently sedated or restrained Subject 1157 to manage the clone's unstable emotions. A stormtrooper was also assigned as a guard. In the first entry for phase 37B, the cloning technician revealed that constant droid attention was necessary due to the Subject's uncontrollable behavior, and Subject 1157's power rendered sedation ineffective. The clone also damaged his tank again with Force lightning.
Shortly before entry 77, an evacuation order was issued due to the return of "Subject 1138," the clone who had previously escaped the facility, and the cloning technician planned to help Subject 1157 accept the memory imprint. Consequently, Darth Vader ordered the abandonment of all nonviable test subjects, and Subject 1157 was scheduled for release into the training chamber. During those final minutes, the cloning technician hoped his life's work had not been in vain. Later, as the Battle of Kamino raged outside Subject 1157's tank, a Force-wielding individual, known as Subject 1138, approached the tank. As the individual drew closer, Subject 1157 futilely pounded the tank with his hand before the other individual struck the tank with a Force push. Subject 1157 died.
Subject 1157, mirroring his clone template, possessed fair skin and displayed an early capacity for stability, distinguishing him from other test subjects. The cloning technician monitoring Subject 1157 expressed satisfaction with the clone's progress. Subject 1157 experienced rapid acceleration and received memory imprints during his development. As he matured, he began to experience disturbing hallucinations, which triggered tremors. As a result, he was systematically sedated. However, his increasing power rendered sedation ineffective. Until Subject 1157's death, the cloning technician continued to try to get the clone to accept the memory imprints.
During the summer of 2010, Subject 1157 was featured on the official website for the LucasArts Star Wars: The Force Unleashed II video game. Later, the site was redesigned as an interactive database, and this content was removed. While Subject 1157 was featured on the website, viewers could see the room outside of a tank from 1157's perspective, listen to audio recordings about his development, see visions of the player character—Starkiller, another clone of Galen Marek—and observe a countdown clock displaying the time in Aurebesh until the next site update. Successfully completing minigames, such as mazes or pong, unlocked visions that served as teasers for the game and included in-game videos and scenes from 2008's Star Wars: The Force Unleashed. The website was updated frequently with new content. This content was also available through the Star Wars: The Force Unleashed II cloning tank website. After "Subject 1138," who was revealed to be Starkiller in The Force Unleashed II, destroyed the tank, viewers lost access to the visions and audio recordings. The countdown clock, though still present, became unreadable. This scene cannot be replicated in the actual game, as the only action possible while passing the cloning tanks is walking, and Subject 1157 is not mentioned in the game.