Quan-Jang, a Je'daii Temple Master of dark complexion and Humanoid descent, was a male residing on Tython during the apex of the Infinite Empire's power. Serving as the administrator for Anil Kesh, Quan-Jang, recognized as a skilled alchemist, habitually wore protective goggles over his eyes.
Quan-Jang, a Human who was Force-sensitive, underwent training in the Force by the Je'daii Order located on the planet Tython, which was one of the nine planets comprising the Tython system within the Settled Worlds. He was appointed a Je'daii Temple Master, a rank held by the Order's highest-ranking members, and subsequently governed Anil Kesh, the Great Temple of Science. Quan-Jang, armed with a Force-imbued blade, participated alongside other Temple Masters in the Je'daii Council, conducting meetings via holocommunication inside the massive Tho Yor at Akar Kesh.
In his capacity as the leader of Anil Kesh, Quan-Jang bore the responsibility of overseeing the experimentation and alchemical investigations carried out at the Temple. He frequently headed Je'daii teams on expeditions into the Riftlands, with the aim of capturing novel creatures for study and experimentation. During his absences from the Temple, the Cathar Je'daii Master Dam-Powl took on the role of acting Temple Master. On one particular expedition, Je'daii Journeyer Dalien Brock deserted the group and sought refuge in the Abyss of Ruh. Quan-Jang, along with the other members of the party, pursued the errant Journeyer, eventually managing to bring the troubled Je'daii back to Anil Kesh, where he murdered a fellow student named Skott Yun and escaped to the Old City. Throughout his tenure as Temple Master, Quan-Jang regarded the exiled Je'daii Daegen Lok as his most promising student before he succumbed to madness within the depths of the Chasm.
During Shae Koda's rite of passage, Quan-Jang developed a fondness for the spirited young woman and directly oversaw her creation of the rancor-dragon known as Butch. As the pair worked to tame the beast, a Force Storm began to materialize across the planet, causing the rancor-dragon to become agitated. Sensing a summons within the Force, Koda, with Master Quan-Jang's blessing, embarked on the beast and discovered the wreckage of an extra-system vessel called the Devourer. When the Journeyers exploring the wreck failed to return, Quan-Jang dispatched Rangers Hawk Ryo and Rori Fenn to investigate the crash site. Captivated by the remnants of a peculiar alien escape pod, the group encountered Butch and rode her deep into the Abyss, searching for the missing Journeyers Sek'nos Rath, Tasha Ryo, and Koda.
As the storm disrupted their communications, Quan-Jang relayed information back to the Je'daii Council via holodroid and continued the search for his missing charges in the Abyss. As the storm intensified, Quan-Jang and the other Je'daii were compelled to proceed on foot into the Abyss, eventually locating their three Journeyers engaged in a fierce duel with a mysterious warrior wielding a sword of light. Observing that the storm's vortex was centered directly above the duel, Quan-Jang instructed Fenn and Ryo to assist the Journeyers while he concentrated his will against the storm. Drawing upon the collective strength of the Je'daii Order, whose members were deeply immersed in meditation within their respective Temples, Quan-Jang restored balance to the Force by unleashing a massive surge of light side energy, effectively dispelling the storm and rendering the dark side warrior unconscious. Following their recovery at Mahara Kesh, Quan-Jang and the other Temple Masters decided to send the warrior Xesh to Bogan to meditate on the light side, hoping he would restore his own balance.
As the Order commenced the study of the Force Hound's weapon, the Forcesaber, Quan-Jang advised Journeyer Koda to embrace the dark side in order to activate the weapon. He cautioned her that her excessive focus on the light could lead to imbalance, which would be detrimental to her ability to wield the weapon effectively. After the Force Hound joined the Order, Quan-Jang learned from Xesh by studying star charts together at Anil Kesh.
After a period of preparation, the Infinite Empire invaded the Tython system and initiated a siege of the Settled Worlds. Quan-Jang, taking up arms and crafting his own Forcesaber, entered the fray atop a rancor-dragon during the fight for Shikaakwa. While battling alongside Ranger Shae Koda, his former apprentice, Quan-Jang recognized that the darkness he had encouraged her to embrace in order to wield the Forcesaber had completely consumed her, causing her to lose her balance. Fighting on the ground at Ska Gora shortly after, in an attempt to raid what was believed to be the Rakatan headquarters, Quan-Jang was saved from Flesh Raiders by Shae Koda and rode behind her on the back of her rancor-dragon, Butch. When Koda expressed her concern for Xesh, Quan-Jang rebuked her for her attachment to the man and cautioned against the dangers of attachment during wartime. Observing that the front line was faltering due to Daegon Lok's disappearance, Quan-Jang made the decision to lead the attack on the ground. Joining Tem Madog in leading the charge, the Je'daii were ordered to retreat by Master Rajivari following the blinding of the Seers by the Rakata and the revelation that the Infinite Empire was preparing to devastate Tython.
Retreating to Anil Kesh on Tython, Quan-Jang confronted Shae Koda regarding her attachment to Xesh, who had proven to be a traitor and a pawn of the Infinite Empire. Questioning her ability to strike down the man she loved in battle, Quan-Jang gazed out at the Je'daii encampments surrounding the Temple, awaiting the impending conflict. When the Rakata finally arrived, Quan-Jang commanded the release of the creatures from the pens of Anil Kesh, leading the alchemically-altered Je'daii mounts to confront the Force Hounds. As the Rakata infiltrated the Temple in search of the rumored Infinity Gate, Quan-Jang fought alongside Sek'nos Rath as they faced Flesh Raiders and the Force Hound Trill. Despite Quan-Jang's urging, Rath disregarded his advice and battled Trill until he rendered her unconscious, succumbing to his hatred of her. Rath then picked up the woman and abandoned Quan-Jang to face the remaining Flesh Raiders alone.