Gaden-Ko was a male Voss individual, specifically a Mystic in training, during the era known as the Cold War.
The offspring of a sculptor and a former Voss commando who sustained injuries inflicted by the Gormak during Gaden-Ko's early years, Gaden-Ko was raised by his grandfather, Dajan-Ko, as per Voss tradition. Dajan-Ko quickly recognized Gaden-Ko's remarkable intuitive abilities. These abilities proved useful in assisting Voss commandos by accurately predicting the movements of Gormak patrols. Subsequently identified as a promising Mystic visionary, he dedicated several years to studying and preparing for his pilgrimage at the Tower of Prophecy.
Seeking an alliance with the Voss, a Jedi Consular known as the Barsen'thor decided to aid Gaden-Ko in his training. The Barsen'thor located him along the Holy Path of Mir as he was beginning his pilgrimage, after he had lost all his bodyguards, and offered him protection during the journey. Appreciative of the Barsen'thor's assistance, Gaden-Ko successfully completed his pilgrimage and became a Mystic. His initial vision revealed that his purpose was to support his new friend and the Republic in the Galactic War against the Sith Empire. The Three, the governing body of Voss, expressed concern that while they had gained a Mystic, they were losing him to outsiders. Gaden-Ko reassured the Three that he would remain connected to them. He conveyed that through his collaboration with the Barsen'thor, he had observed wisdom and kindness within the Republic, advocating for an alliance between Voss and the Republic. Gaden-Ko later acquired a small group of Voss Commandos, healers, and interpreters as he became a member of the Barsen'thor's crew. Following the defeat of the First Son, Gaden-Ko suggested to the Barsen'thor, Master Jaric Kaedan, and Satele Shan that Jedi could be sent to Voss to foster mutual learning and understanding.
Gaden-Ko belonged to the first generation that grew up in a Voss-Ka where encounters with alien outsiders were commonplace. He displayed a consistent interest in these foreigners, even cultivating a friendship with the Republic ambassador. In comparison to other Voss, Gaden-Ko was perceived as somewhat impulsive and lacking patience.
Within the flashpoint titled "The Nathema Conspiracy," if the Outlander is a Jedi Consular who has aligned themselves with the dark side of the Force, Gaden-Ko will attempt to thwart the player's actions and will join the Order of Zildrog, led by Vinn Atrius. He will then be sacrificed by GEMINI 16 on Nathema to provide the energy needed to awaken Zildrog. Conversely, if the Jedi Consular maintains their allegiance to the light side, the player will instead encounter Sophia Farash, while other classes will face antagonists derived from their respective class storylines.