A male Human Jedi Master named Jun Seros dedicated his life to the service of both the Jedi Order and the Galactic Republic. During the tumultuous times of the Great Galactic War and the subsequent Cold War, he held the esteemed position of the Order's battlemaster. Celebrated not only for his exceptional lightsaber skills but also for his unwavering devotion to the Jedi and the Republic, he shone as a prominent figure among the Jedi Order's leaders and Masters throughout the War and the Cold War that followed.
Jun Seros, a Force-sensitive Human, underwent rigorous training in the ways of the Force under the guidance of the Jedi Order. He served with distinction as a Jedi Knight for more than ten years, mastering the arts of warfare and lightsaber combat while always abstaining from striking with harmful intent. When the reconstituted Sith Empire emerged from the depths of the Unknown Regions, igniting a galaxy-wide war, Seros was elevated to the rank of Jedi Master. Recognizing the gravity of the threat, he earnestly wielded his weapon for the first time in his life. Unlike some of his fellow Jedi, Seros embraced the conflict and served as a general within the Republic Military's forces. The Jedi High Council designated Seros as the Order's battlemaster, entrusting him with the training of countless Jedi on the battlefield. His strategic brilliance and courageous interventions ensured his triumph on every front he commanded.
The war reached its conclusion during the Sacking of Coruscant by the Sith. The Republic's decision to sign the Treaty of Coruscant was met with strong disapproval from Seros, who openly opposed honoring the agreement, viewing it as an act of folly.
During the Cold War, he tirelessly campaigned against placing trust in the Sith's adherence to the treaty terms. Throughout this period, he proved to be an invaluable advisor to Supreme Chancellor Dorian Janarus, forging a strong bond of friendship that he later exploited to pursue a rising bounty hunter known as the Grand Champion of the Great Hunt.
Another close friend of Seros was the esteemed Jedi Master Kellian Jarro, a renowned warrior celebrated for personally eliminating one hundred Mandalorians during the Sacking of Coruscant. Jarro's actions during the sacking made him a target of Mandalorian animosity, leading to a bounty being placed on his head. Jarro eventually became the final target of the Great Hunt, and the bounty was claimed by the competition's champion. Seros, driven by vengeance, initiated a relentless pursuit of his friend's killer.
Seros initially attempted to ensnare the Hunter on Quesh, using a fabricated endorsement from Adascorp as bait. The Hunter, motivated by mercenary instincts, arrived only to discover the trap and find themselves surrounded by SIS agents. Seros observed the scene via hologram as the Hunter decimated the entire strike team. Seros made a cryptic promise that he was not finished, but the Hunter dismissed his threat and ended the communication.
Seros subsequently dispatched another team, led by Adeline Marr, to Nar Shaddaa in search of the Hunter. The team confronted the other Grand Champions—Bloodworthy, Jewl'a Nightbringer, and Defenestrator—who were planning a celebration for the Hunter's successful Blacklist bounties. However, the Champions refused to betray their comrade's location. The trio was brutally killed, just as the Hunter arrived. Seros, once again monitoring via hologram, offered the Hunter a final chance to surrender. When his terms were rejected, the Hunter eliminated the entire team before vowing to hunt down and kill Seros. Unfazed, Seros vowed to make the Hunter regret defying him.

Following these events, Seros orchestrated a scheme to frame the Hunter for a litany of fabricated crimes, branding them as the Republic's Most Wanted in an attempt to expose the Sith's true nature. Bounty hunters across the galaxy began vying for the million-credit bounty on the Hunter's head, while the Empire severed all ties with the Hunter. However, the Hunter was soon after employed by Darth Tormen, who offered the chance for revenge against Seros and Janarus, who had publicly denounced the Hunter.
The Hunter assisted Tormen in subduing Corellia by capturing rebel leaders and forcing them to sign a treaty that mandated Corellia's secession from the Republic. Master Seros recognized the treaty as a ruse to lure the Supreme Chancellor from Coruscant to ratify it and convinced Janarus that he could rally the Green Jedi against the Sith invasion of the planet. He later encountered his target on Corellia. Instead of seeking assistance from his fellow Jedi in apprehending the mercenary, he dismissed them. He and the Hunter exchanged words before engaging in combat. Despite his mastery of the Force, Seros was defeated. As he lay dying, Seros boasted that while he may have failed to arrest the Hunter, he had at least distracted the Hunter while his allies rescued Darth Tormen's captives and nullified his fraudulent treaty. However, he was mistaken, as Tormen slaughtered the entire team of Green Jedi. Determined to deny Seros the satisfaction of a final victory, the Hunter revealed that the entire operation was not just to kill him, but to get to the Supreme Chancellor and they both walked into a trap. Realizing the consequences of his actions, Seros attempted to rise, only to be killed by the Hunter.
Chancellor Janarus later condemned Seros's actions against the Hunter, asserting that he had no right to abuse his authority and deceive the public for personal vengeance.
Jun Seros was a profoundly dedicated Jedi Master, characterized by his unwavering belief in justice and his staunch opposition to the Sith. These qualities were most evident during the Cold War, as he refused to trust that the Sith would abide by the Treaty of Coruscant. This conviction also fueled his relentless pursuit of Corellia's liberation, leading him to persuade Supreme Chancellor Janarus to authorize a final effort by the Jedi to reclaim the planet. He held steadfast faith in the power of the Jedi and the all-encompassing strength of the light side. He also refused assistance from his fellow Jedi during his final duel, sending them elsewhere to their fates while he confronted his nemesis.
Despite his status as a Jedi Master, Jun Seros displayed a darker side in his pursuit of the Grand Champion of the Great Hunt. Persistently assuming that his adversary would surrender easily, he resorted to murdering others and dispatching teams of both SIS agents and Jedi to capture them. He firmly believed that no criminal should escape justice and should face the consequences of their actions, yet he seemed to have no qualms about murdering individuals he deemed criminals (specifically, the other Great Hunt champions). What began as a commitment to justice evolved into an all-consuming obsession that bordered on a descent to the dark side as he relentlessly pursued his target.
However, in the end, he remained true to his Jedi nature, sacrificing himself for the sake of Corellia. Among his final words, he declared that while he may have failed to kill the Champion, he had succeeded in undoing everything the hunter had accomplished until then, and would now return peacefully to the Force. He may have also regretted his darker actions, since when the Hunter revealed that Janarus was their next target, Seros realized his pride blinded him and died regretting that he had led his friend to his doom.
As one would expect from a Battlemaster of a Jedi Order engaged in war, he possessed exceptional skill in various forms of combat. During his final duel, he demonstrated remarkable awareness, freezing a rocket at point-blank range and destroying it. He shielded himself from a close-range flamethrower using only the Force, after having previously deflected a barrage of blaster shots with ease.
Following this brief exchange, he ignited a second lightsaber—demonstrating his proficiency in Jar'Kai—and launched a fierce assault on the Grand Champion of the Great Hunt, displaying an immense connection to the Force as he imbued each of his attacks with great power. Although this was insufficient to defeat the Bounty Hunter, he held his own for a considerable time against an individual who had slaughtered countless Jedi Knights and Masters on his way into the Green Jedi Enclave.
After wounding Seros, the player is presented with dialogue options before his death. If the player chooses to kill him without uttering another word (the dark side option), the scene concludes abruptly. However, selecting either of the two neutral dialogue options leads to further exchanges. Choosing the neutral dialogue results in Seros boasting that his comrades are en route to the Grand Assembly to liberate Tormen's captives and invalidate his fraudulent treaty. The light side dialogue involves the Hunter pointing out Seros' hypocrisy regarding the Jedi principle of non-attachment, which fueled his vendetta. Seros retorts that the Hunter should not escape justice for their crimes and should face the consequences of their actions. The dark side dialogue has the Hunter gloat that Chancellor Janarus is next, having used Seros to lure him out. Seros attempts to rise, but the Hunter kills him, mockingly thanking him for his contribution.