Sintas Vel, originating from the planet of Kiffu, was a female Kiffar who embarked on a career as a bounty hunter at a young age. During her time as a bounty hunter, Sintas encountered Boba Fett, another bounty hunter, with whom she developed a romantic relationship and eventually married at the age of eighteen. For three years, they resided on Concord Dawn, where Fett worked as a Journeyman Protector and Sintas gave birth to their daughter, Ailyn. Their relationship ended when Fett's superior officer sexually assaulted Sintas, leading Fett to kill the officer and be exiled from Concord Dawn. This event led to their divorce, leaving Sintas to raise their daughter on her own. Shortly before Ailyn's sixteenth birthday, Sintas accepted a job to buy her daughter a present, a decision that resulted in her being trapped in carbonite for nearly four decades, until her granddaughter, Mirta Gev, discovered her on Phaeda. After being rescued, Sintas was brought to Mandalore, but she suffered from blindness and amnesia due to the long period of carbon-freeze. With the assistance of her granddaughter, a remorseful Boba Fett, and Gotab, a Jedi Knight who had become a Mandalorian, Sintas regained her sight and memories, allowing her to reconcile with Fett and bond with Mirta.
Born on the planet of Kiffu in 34 BBY, Sintas Vel was a female Kiffar. In her early years, she chose to become a bounty hunter. During her career as a bounty hunter, Sintas crossed paths with Boba Fett, also a bounty hunter. Their relationship blossomed into love, and they married in 16 BBY, with Sintas at eighteen and Fett at sixteen. Despite Sintas's concerns about Fett's youth, he insisted that her beauty, marksmanship, and trustworthiness were all that mattered. They exchanged the succinct, four-line Mandalorian marriage vows—though neither understood Mando'a at the time—and Fett gifted Sintas a heart-of-fire gemstone from Kiffu, which was believed to hold a piece of their souls in Kiffar culture, which she wore as a necklace.
Sintas and Fett made their home on the agricultural world of Concord Dawn, where Fett transitioned from bounty hunting to becoming a Journeyman Protector, one of the planet's constables responsible for upholding the law. A year later, in 15 BBY, they welcomed their daughter, Ailyn. However, around this time, Sintas was sexually assaulted by Lenovar, Fett's superior officer and a man Fett considered a friend. Sintas kept the assault a secret, even from Fett, but he eventually learned the truth. Despite Sintas's pleas, Fett killed Lenovar, resulting in his arrest, imprisonment, and exile from Concord Dawn. Fett's decision to protect Sintas by not revealing Lenovar's crimes to the magistrate led to his conviction. The exile, coupled with intense arguments and accusations—including Fett questioning Ailyn's paternity—destroyed their marriage, leading to their separation when Ailyn was two years old, leaving Sintas to raise her daughter alone. To support Ailyn, Sintas continued her work as a bounty hunter.
Years afterward, Boba Fett dispatched Connor Freeman, a clone relative of Jango Fett, to Concord Dawn with instructions to locate Sintas and shield her from unidentified assassins targeting Fett's family. Connor successfully located Vel's residence on Concord Dawn. While Connor was taken aback by the presence of Sintas' young daughter at the door, Sintas emerged from behind him, demanding to know his purpose. Before he could provide a comprehensive response, a Devaronian strike team launched an assault from a landspeeder, and Connor demonstrated his genuine intentions by aiding them in neutralizing the threat. After relocating to a fortified safehouse within the town, Sintas began sharing her observations about Connor's striking resemblance to Fett, culminating in a kiss. Later, while enjoying a late dinner, Connor stumbled upon a family holo, revealing that he had inadvertently kissed his brother's wife. Upon being confronted, Sintas recounted Fett's tenure as a Journeyman Protector and the dissolution of their marriage, with Ailyn playfully teasing them about the kiss. Suddenly, the safehouse door was breached, prompting Connor to employ his cybernetic arm to deflect the intrusion. As Governor Purton unveiled himself as the mastermind behind the assassination attempts on Fett and his family, Connor and the Vels sought refuge from his grenades in the storage basement, where Sintas furnished him with a set of yellow Mandalorian armor. Purton pursued them, leading a strike team into the basement. Following the elimination of his guards, Purton disclosed his motive: revenge for Fett's killing of his son, Lenovar. In response, Sintas revealed that Fett had acted in retaliation for Lenovar's brutal assault on her, a fact Fett had concealed during the trial to shield her. Dismissing her account as fabrication, Purton attempted to strangle her, compelling Connor to fatally shoot him. Sintas then bid Connor farewell with a kiss, explaining that Fett and individuals like him only brought her misfortune. Unbeknownst to her, Fett was silently observing his wife and daughter through the trapdoor. Subsequently, he departed with Connor, without revealing his presence to Sintas.
Sometime before 1 ABY, a canister containing a holo-image of Sintas, Fett, and their daughter, belonging to Sintas, was pilfered by the criminal known as Pizztov. This image, the sole depiction of the three as a family, spurred Sintas to pursue Pizztov to the city of Bidamount, where he was attempting to extort over six million credits from Boba Fett by threatening to auction it off publicly in one of Bidamount's auction houses. Breaching the floor of Pizztov's quarters, Sintas demanded the return of her property at blaster point, shooting one of Pizztov's bodyguards when he attempted to intervene. Simultaneously, Fett arrived, rescuing Sintas from a second guard's assassination attempt, though his intention was to seize the canister for himself. Pizztov fled, and Sintas pursued him, eventually catching and shooting him in the back; before she could reclaim her stolen property, Fett shot the canister from her hand. Pizztov attacked Fett with one of Sintas' blaster pistols, though he missed and was killed by Fett. Wounded, Sintas pleaded with Fett not to take the canister, and Fett explained that the reason he'd fired was because the canister had been rigged to explode if not opened correctly. Upon opening the canister and seeing the holo of his family along with Sintas' tearful reaction, Fett decided to return the canister to Sintas instead of destroying it as he had originally planned. Though she was grateful, Sintas was also dismayed when Fett left her again, this time wounded. Despite this second abandonment, Fett's actions in recovering the hologram gave Sintas hope that he still in some way cared for her.
Shortly before Ailyn's sixteenth birthday in 1 ABY, Sintas accepted a high-paying bounty hunting job. She intended to use the earnings to take her daughter to Coruscant to see the city and purchase her nice birthday gifts. However, Sintas never returned from this mission. She was captured and sedated by a man seeking to ransom her, potentially recognizing her as Boba Fett's former wife. Believing Sintas to be dead, Ailyn developed a hatred for Fett, blaming him for abandoning them. She became a bounty hunter herself, dedicating her life to hating and attempting to kill her father. She even killed a clone she mistook for Fett and raised her own daughter, Mirta, to despise Fett. Ailyn also retrieved the heart-of-fire necklace Fett had given Sintas from the man believed to have killed her, eventually passing it on to Mirta as part of another assassination attempt on Fett. Following Ailyn's death at the hands of Jacen Solo in 40 ABY, Mirta and Fett formed a fragile alliance and sought to uncover the truth about Sintas' fate. During an evening at the Oyu'baat tapcafe on Mandalore, they were approached by the elderly Mandalorian Gotab, a Kiffar with the ability to read memories from the heart-of-fire gem Mirta possessed, hoping to shed light on Sintas' death. Gotab's insights and Mirta's subsequent research led them to the planet Phaeda, where they discovered Sintas frozen in carbonite among the possessions of the deceased gangster, Hidu Rezodar. Fett and Mirta brought Sintas back to Mandalore and revived her from carbon-freeze after nearly forty years, with the assistance of Fett's doctor, Beluine. Initially, Sintas experienced severe confusion, dizziness, sensitivity to sound, and blindness, and it became apparent that she was also suffering from amnesia, unable to recall significant portions of her life or even her own identity.
Despite appearing to be in her mid-thirties due to the carbon-freezing process, Sintas was forced to rely on the kindness of others in her impaired state. She lived on Mandalore at the home of Goran Beviin—Fett's closest friend—and was cared for by her granddaughter, Mirta, and Beviin's partner, Medrit. Mirta returned her heart-of-fire necklace, and the others, including Fett, attempted to jog her memory, but with little success. It was only when Jedi Knight Jaina Solo—who was on Mandalore seeking training from Fett to confront her Sith Lord brother, Jacen—enlisted the help of Gotab, who was revealed to be a Jedi-turned-Mandalorian skilled in Force healing, that real progress was made. Gotab used the Force to restore Sintas' sight and recover her lost memories.
With her memories restored, Sintas vowed to avenge Ailyn's death if the opportunity arose. She also explained the circumstances of her divorce from Fett to Mirta, revealing that she had never told Ailyn the truth or encouraged her hatred of Fett. Instead, Ailyn had filled in the gaps herself after Sintas' disappearance, portraying Fett as more heartless than he was. When Mirta married Ghes Orade, Sintas attended the celebratory feast at the home of Orade's father, Novoc Vevut. Sintas was also able to reconcile with Fett, who already felt remorseful for his role in their separation and the abandonment of his daughter. He gave her another heart-of-fire gem, a rarer and more valuable blue-colored one, along with a portfolio of stock shares and properties, allowing her to choose whether to keep or sell them, ensuring she would never have to hunt bounties again. Fett also assured her that she was welcome to stay on Mandalore for the rest of her life, regardless of her decision.
As a Kiffar, Sintas possessed the unique psychometric abilities of her people, along with a distinctive set of qukuuf facial markings in the form of three black stripes on each cheek, presumably inherited from her mother in accordance with Kiffar tradition. Sintas was a skilled marksman, capable of wielding two blaster pistols simultaneously, as demonstrated during her mission to retrieve the stolen hologram from Pizztov. With dark hair, blue eyes, high cheekbones, and a small pointed chin, Sintas was considered an attractive woman, though she did not rely on her looks in her bounty hunting career. Boba Fett once remarked, "he could never get over how beautiful Sintas was." Despite being a tough and ruthless bounty hunter—willing to risk the life of an innocent bystander to reclaim her family's stolen hologram—Sintas showed a softer side to those she cared about, particularly her daughter Ailyn, granddaughter Mirta, and lover Boba Fett, whom she affectionately called "Bo" even after their divorce, and who referred to her as "Sin" in return.
The character "Sintas" first appeared in the short comic, "Outbid But Never Outgunned" from Dark Horse Comics' Star Wars Tales 7, a story centered on Boba Fett and offering a brief glimpse into his previously mysterious past. While the canonicity of the first twenty issues of Tales was questionable at the time, Sintas' character was later canonized with appearances in the Star Wars Gamer article, Unusual Suspects, and the Star Wars Insider article, The History of the Mandalorians, where she was first identified as "Sintas Vel". She later featured in the Star Wars: Legacy of the Force novel series, receiving mentions in Legacy of the Force: Bloodlines and Legacy of the Force: Sacrifice by Karen Traviss, before making a full appearance in Traviss' third Legacy of the Force novel, Legacy of the Force: Revelation, where her character and history were further developed.