The Cuy'val Dar consisted of a group of one hundred people that Jango Fett, a Mandalorian bounty hunter, called upon to journey to the aquatic planet of Kamino. Their purpose was to provide training to the clone troopers intended for service in the Galactic Republic. Seventy-five of these individuals, both men and women, were Mandalorians, just like Fett. The term Cuy'val Dar translates from the Mandalorian language to "those who no longer exist." This name arose from the necessity for these individuals to vanish to Kamino, severing all ties with the outside galaxy due to the clandestine nature of the Grand Army of the Republic's development. For about a decade, these one hundred training sergeants secretly prepared the ten thousand clone commandos until they were deployed during the Battle of Geonosis in 22 BBY, an event that ignited the Clone Wars across the galaxy. Once their contracts concluded, many Cuy'val Dar trainers returned to their former lives. However, a select few continued their work with the Republic, training subsequent generations of clones on Kamino and later providing standard clone soldiers with commando skills through cross-training.
Almost fifty years later, specifically in 25 ABY, Kubariet, a New Republic Intelligence agent and Jedi Knight, engaged in a meeting with Mand'alor Boba Fett on Vorpa'ya during the opening year of the Yuuzhan Vong War. During this encounter, Kubariet requested that Fett establish a new Cuy'val Dar group. This new group would consist of seasoned Mandalorian commandos tasked with training planetary militias to defend against the Yuuzhan Vong.
Back in 32 BBY, Count Dooku of Serenno, previously a Jedi Master who abandoned the Jedi Order and succumbed to the dark side of the Force, becoming the Sith Lord known as "Darth Tyranus," persuaded Jango Fett, a Mandalorian bounty hunter, to serve as the genetic template for a clone army to be cultivated on Kamino. Fett, a highly skilled soldier in his own right, understood the necessity of diversity within an effective army, including troops capable of handling more perilous and intricate missions. Consequently, Fett sought out individuals from across the galaxy to train elite clone commandos, each possessing specialized skill sets ranging from military and survival expertise to tracking and communication capabilities. This group of one hundred trainers, seventy-five of whom were Mandalorians like Fett, became known as the Cuy'val Dar, which in the Mandalorian language of Mando'a translates to "Those Who No-Longer Exist." The name's origin lies in the Cuy'val Dar's need to abandon their previous lives and disappear to Kamino for an indefinite period, without any contact with the outside galaxy. They were largely presumed dead or missing, having left behind family and friends without providing any explanation.
Many members of the Cuy'val Dar had backgrounds considered unconventional by the standards of the Galactic Republic. Their ranks included bounty hunters, mercenaries, and assassins. However, upon answering Fett's call to Kamino, this diverse group assumed the role of training sergeants for the commandos who would form the special forces of the Grand Army of the Republic. With the exception of Fett, who personally trained the one hundred Alpha-class Advanced Recon Commandos around 30 BBY, each Cuy'val Dar sergeant was assigned a company of one hundred and four clone cadets to transform into commandos. The education of these commandos-in-training was not limited to their assigned sergeants; several Cuy'val Dar members possessed unique skills that they shared with the trainees. Mij Gilamar, a sergeant who was also a trained doctor, instructed the clones in combat medic techniques. Kal Skirata, another Mandalorian known for his unconventional fighting methods, taught the clones counter-insurgency tactics. Llats Ward, a sergeant dedicated to warfare, had memorized the campaigns of famous leaders in Mandalorian military history, using these historical events in his teachings as a combat skill instructor for the clone troopers.
The Cuy'val Dar trainers had a significant impact on the clones they trained, extending beyond skill instruction to influencing their personalities. Walon Vau, a Mandalorian sergeant, believed in rigorous training to prepare his men for the realities of combat, turning them into survivors on a primal level. His methods were validated by the high survival rates of squads trained by Vau following their initial deployment. The commandos of Delta Squad felt genuine gratitude towards Vau for his training, while RC-3222, known as "Atin," resented and hated Vau for his brutality. Kal Skirata adopted a different approach, encouraging his men and treating them as sons, while still being dutiful in his training. Rav Bralor, another Mandalorian sergeant, shared a similar approach with her squads. Both Skirata and Bralor were regarded with familial affection by their clone trainees. Almost all of the Mandalorian training sergeants, regardless of their training styles, instilled a sense of Mandalorian identity in their charges, teaching Jango Fett's clones about their Mandalorian heritage, which many clone commandos embraced enthusiastically. This was not exclusive to the Mandalorian trainers; commandos trained by a Corellian readily adopted Corellian traits and cultural elements, and the same applied to clones trained by sergeants from Concord Dawn, such as Cort Davin, a former Journeyman Protector.
One Mandalorian instructor, considered among the best in the Cuy'val Dar, trained a clone soldier named Kaddak, who took his name from Kad Ha'rangir, the ancient destroyer god of Mandalorian mythology. Kaddak and his Cuy'val Dar instructor developed a strained relationship that eventually led to a physical altercation. Kaddak killed the instructor using only his bare hands, leading to his incarceration by the Kaminoans and subsequent testing. Rumors suggested that Kaddak was ultimately killed by the Kaminoans, but he actually escaped Kamino and settled on Ostor.
The Grand Army was finally deployed in 22 BBY, approximately ten years after its creation. Due to the rapid deployment, many Cuy'val Dar sergeants were unable to bid farewell to the commandos they had trained, some of whom never returned from the battle on Geonosis. With the Kamino contract ending after the Clone Wars began between the Republic and the Separatist Confederacy of Independent Systems, most of the Cuy'val Dar went their own ways, returning to their previous lives after nearly a decade, with a substantial sum of credits for their services. However, Kal Skirata secured a position as a military advisor to the Grand Army's Special Operations Brigade through a deal with Jedi Master Iri Camas, and later with Director of Special Forces, Jedi General Arligan Zey. Kligson, a non-Mandalorian Cuy'val Dar sergeant, eager to join the fight, enlisted in the Grand Army of the Republic, becoming one of the Republic's few non-clone officers and fighting on the frontlines at Sluis Van and Praesitlyn. By the second year of the war, Walon Vau had also returned to the Republic's service, participating in a strike against Jabiimi terrorists on Coruscant. Vau also became involved in cross-training standard clone troopers with commando skills, alongside Mij Gilamar and Wad'e Tay'haai, who were re-employed as Cuy'val Dar sergeants.
Members of the Cuy'val Dar were also involved in training clones on Kamino as part of the enhanced training program initiated by ARC trooper Alpha-17. Cort Davin was responsible for teaching Clone Commander Bacara of the Galactic Marines the traditions and culture of the Journeyman Protectors. Mandalorian trainers imparted elements of their culture to Clone Captain Rex, granting him the right to wear jaig eyes on his armor. Vhonte Tervho, a Mandalorian huntress, taught her skills with dual DC-17 blasters to over a thousand aspiring clone commanders.
After the Kamino contract concluded, several Mandalorian members of the Cuy'val Dar continued to collaborate in a secret and personal mission to assist the clones they had trained. Under the unofficial leadership of Kal Skirata, former Cuy'val Dar trainers Walon Vau and Rav Bralor attempted to find a way to stop the accelerated aging affecting the clones by kidnapping Kaminoan scientist Ko Sai. The former Chief Scientist of Kamino defiantly took her own life at Skirata's home on Mandalore, Kyrimorut, a refuge Bralor had secured for Skirata and any clone wishing to desert the Grand Army for freedom. Mij Gilamar, another Cuy'val Dar sergeant and doctor, attempted to continue Ko Sai's research, acquiring additional research from sources like Arkanian Microtechnologies with the help of the Null-class ARC troopers, before the group abducted the Separatist geneticist Ovolot Qail Uthan and persuaded her to assist them. Their efforts eventually succeeded in finding a cure for the clones' accelerated aging, which was then administered. Skirata, Gilamar, Vau, and Bralor, along with former Cuy'val Dar comrade Wad'e Tay'haai, spent considerable time at Kyrimorut in the weeks and months following the transformation of the Republic into the Galactic Empire under Emperor Palpatine. While Skirata and his comrades distanced themselves from the Empire and its presence on Mandalore, former Cuy'val Dar trainers Dred Priest and Isabet Reau, now members of the renegade Death Watch, allied themselves with the Empire as part of leader [Lorka Gedyc]'s plan to strengthen the Mandalorians. Gilamar later killed Priest in Keldabe, the Mandalorian capital city, after his Death Watch ties were revealed.
Years later, during the initial year of the Yuuzhan Vong War, Kubariet, a New Republic Intelligence agent and Jedi Knight, met with Mand'alor Boba Fett on Vorpa'ya in the Mandalore sector. Kubariet reminded Fett of the Cuy'val Dar that his father, Jango, had established, and suggested that he create a new group of Cuy'val Dar consisting of his most experienced commandos to train planetary militias to resist the Yuuzhan Vong.
The Cuy'val Dar were initially mentioned in Republic Commando: Hard Contact, a novel written by Karen Traviss in 2004. This novel established their role as trainers for the clone commandos personally selected by Jango Fett. Walon Vau, a member of the Cuy'val Dar, made brief appearances in the loading screens of the 2005 video game Star Wars: Republic Commando, which Hard Contact was originally intended to complement. The Cuy'val Dar made their first full appearance in Traviss' short story Omega Squad: Targets and her second novel in the Republic Commando series, Republic Commando: Triple Zero, which featured sergeants Kal Skirata and Walon Vau as prominent characters. Members of the Cuy'val Dar also appeared in Traviss' later novels, including Republic Commando: True Colors, Order 66: A Republic Commando Novel, and Imperial Commando: 501st. The Cuy'val Dar were also mentioned in Traviss' e-novella, Boba Fett: A Practical Man.
"Clone Cadets," the opening episode of the third season of Star Wars: The Clone Wars, introduced the characters of El-Les and Bric. Although not explicitly identified as Cuy'val Dar members in the episode, these two mercenary bounty hunters are employed by the Republic to train clone troops on Kamino, a role previously associated with members of the Cuy'val Dar.
Karen Traviss noted in her blog that "[the Cuy'val Dar] either needed the fee very badly, or they were insanely loyal to Jango, or they wanted to disappear for reasons best known to themselves...and so on."