Once known as Madelin Sun, "The Archivist" was a Force-sensitive female human who lived during the Galactic Empire's reign. She had previously held the position of sava at the University of Bar'leth. Possessing a subtle connection to the Force, she could sense its presence but lacked the ability to wield Force powers. She maintained the belief that the light side and the dark side were essentially the same. In time, Madelin would become known primarily by a title that reflected her true nature. When Qi'ra, the leader of the Crimson Dawn crime syndicate, assembled various individuals and groups on her flagship, the Vermillion, Sun was among the attendees. Qi'ra shared her knowledge of the Sith and the true state of the galaxy, controlled by Sith Lords Darth Sidious and Darth Vader, informing her allies of her strategy to overthrow them and reshape the galaxy's power dynamics. Sun documented these events in a holocron accessible through either the light or dark side of the Force, which was later discovered and reviewed by siblings Luke Skywalker and Leia Organa following the Empire's collapse.

During the Republic Era, Madelin Sun was employed as a sava at the University of Bar'leth. With a slight sensitivity to the Force, she dedicated herself to investigating artifacts linked to the Dark side of the Force. Regrettably, after Order 66 was executed and the Empire assumed control of the galaxy, all evidence pertaining to the Jedi was slated for removal, leading to Sun's dismissal.

Later on, in the Imperial Era, Sun found work as a junk dealer on Antillion. One day, she was approached by Han Solo, a smuggler, who inquired about her possession of an urn containing the ashes of a despised rival of Jabba the Hutt. Sensing potential trouble, Sun dismissed the smuggler. However, her shop was subsequently inspected by stormtroopers who discovered an old artifact prohibited under Order 66 Codicil Nine. As one trooper informed Sun they would report the incident, the soldiers were shot down by a mysterious woman who introduced herself as Qi'ra.
Qi'ra informed Sun that she was aware of her work and questioned why the Empire had outlawed the study of the Force following the disappearance of the Jedi Order. Sun explained that the Empire needed to instill fear within the populace and to achieve this, they had to eliminate the hope that the Force and Jedi represented, as Emperor Palpatine had made the very concept a capital offense.
As their conversation continued, Qi'ra revealed to Sun that Palpatine was in fact the Sith Lord Darth Sidious. Realizing that her life had been unjustly taken from her, Sun decided to join Qi'ra aboard her ship. The sava was astonished to find numerous ancient Sith artifacts within Qi'ra's vessel. Ultimately, Qi'ra persuaded Sun to serve as her dark side expert in an effort to devise a strategy to defeat the Emperor.

Qi'ra expressed her belief that some Jedi had survived the Great Jedi Purge, notably Master Yoda, as the Empire had never announced his death. She tasked Sun with the mission of locating him. Sun was granted all necessary resources to find the missing Master, including several old artifacts. She utilized her skills to research the known facts about him, such as his last known location, which, thanks to Qi'ra's information, she discovered was not the Battle of Kashyyyk but Coruscant.
Given Master Yoda's distinctive appearance, he would have needed discreet assistance from a powerful source to vanish from Palpatine's grasp. Realizing that it was most likely the late Bail Organa who had aided Yoda's escape, believing that he transported Yoda on the Corellian corvette known as the Tantive III, Sun reasoned that someone who had been on that ship that day must still be alive. After examining various flight records, she eventually discovered that Jeremoch Colton was still alive and imprisoned on the Accresker Jail. With the help of an Imperial officer secretly working for Crimson Dawn, Sun managed to enter Colton's cell and interrogated him using a thought dowser, which inflicted increasing pain as he resisted revealing what he knew. Colton eventually relented and told Sun that Yoda had later departed on his own vessel to the Sluis sector.

Following further research, she discovered an academic paper from the High Republic Era describing a world called Dagobah, which appeared to be strongly connected to the Force. Sun traveled to the planet alone and immediately sensed its astonishing aura. She was also attacked by a native creature. After being mysteriously saved by what seemed to be luck, she found a cave on the planet. After entering it Sun saw visions that cleared her view on the Force and also changed her appearance, her skin turned to a pale green, her hair turned white, and her left eye became solid white. She soon left the planet after realizing that not only was Master Yoda indeed on Dagobah but that his location needed to be kept a secret as he was the one who saved Sun from the creatures on the planet and led her to the cave. After returned to Qi'ra she told her that Yoda was dead.

Sun eventually assisted Qi'ra in locating the Knights of Ren, who were soon persuaded to join Crimson Dawn and their cause. Following the auction for Han Solo and the battle over Jekara, Sun was present on the Vermillion, where Qi'ra informed her allies about the Empire and their plans to defeat them. Around this period, Sun also contacted Kho Phon Farrus, hoping that the archaeologist would retrieve the artifact known as the Spark Eternal for Crimson Dawn.
Years after the Fall of Crimson Dawn and the failure of Qi'ra's plan, Sun recorded the story on a Holocron, calling it a tragedy.
Madelin Sun was a human female. She had pink hair and beige-pink skin. After her experience at the Cave of Evil her hair turned white and her skin became pale green. Madelin Sun was deeply passionate about her profession, viewing it as her life's purpose. This dedication led her to retain one of her old artifacts of study after becoming a junk seller, despite its status as illegal contraband under Imperial law. Her desire to continue her research work was the primary motivation behind her decision to join Lady Qi'ra and Crimson Dawn.
Being Force-sensitive, Sun was particularly drawn to studying the Dark side of the Force, which she considered closer to how people actually acted. After her experience in the Cave of Evil on Dagobah, Sun's understanding became richer, as she realized that if the dark side showed how people normally are, the Light side of the Force represented what people could be. She also understood that Yoda choose to teach her this lesson instead of letting her die on Dagobah, which made her keep the Jedi Master's location a secret even if revealing it could give her back her old life, this decision made her feel happy for the first time in a long time.
Madelin Sun possessed a mild sensitivity to the Force, meaning that while she could not perform the powerful feats and displays of other force users, she could sense the Force around things. She could sense the Force in various artifacts and could even tell if they were connected to the light side or dark side of the Force. Sun was also able to sense the strong connection to the Force that Dagobah had, claiming that she could almost see the web of life connecting all living things.
Beyond this, Sun's greatest strength was her research ability. Thanks to her time as a sava, she was among the best researchers in the galaxy during the Imperial Era. Perhaps her greatest achievement was using her abilities with Crimson Dawn's resources in order to find a way to track Master Yoda and find his hiding place. She understood that Yoda needed private help from someone powerful to escape from Darth Sidious without being captured and Sun was later capable of tracking one of the only people related to Yoda's journey from Coruscant before his hiding.

Madelin Sun made her initial appearance, though unidentified, in the fifth issue of the Star Wars: War of the Bounty Hunters comic miniseries, penned by Charles Soule, and released on October 13, 2021. She was subsequently identified as the Archivist in a StarWars.com article previewing the first issue of the Star Wars: Crimson Reign miniseries, also written by Soule, on October 21, 2021. On December 21, 2021, her name was revealed in a StarWars.com article providing details of the comics to be released in March 2022.
Soule later disclosed in his monthly newsletter that her design was inspired by unused concept art by Iain McCaig for a Sith Witch in Star Wars: Episode I The Phantom Menace.