Kortanio, a Kessurian and follower of the Path of the Open Hand cult, journeyed into the Galactic Frontier to serve the Path. They were absent when the cult met its tragic end on their native world of Dalna in 382 BBY. Sometime between the Path's demise and approximately 381 BBY, Kortanio, along with their partner Esstrop, were among the few Path members located by pirate chief and former Path affiliate Marda Ro, subsequently joining her organization. Following this, Ro unveiled to them a being known as the Great Leveler.
Alongside Esstrop, the human Milan Stor, and the Twi'lek Fori Nagor, Kortanio was a pirate serving Ro. At a point in time that occurred no earlier than 379 BBY, they participated in a raid on a displaced persons camp. During the attack, Nagor presented refugees captured by the raiders to Ro within the Gaze's grand hall, but Ro commanded her to release them. Kortanio and Esstrop later escorted the Evereni siblings, Vika and Velya Faer, to the throne hall for a rendezvous with Ro. At one point, Ro included Kortanio in a recorded message intended for her progeny, which her great-great-grandson Marchion Ro had listened to by 252 BBY.
Kortanio, a Kessurian, embraced the Path of the Open Hand cult prior to 382 BBY. During their tenure with the Path, they traversed the Galactic Frontier in an exploration vehicle, spreading the Path's doctrines alongside their companion Esstrop. Consequently, they were not present on the Path's birthplace, Dalna, during the Night of Sorrow in 382 BBY, which resulted in the Path's downfall, and they remained ignorant of the event.
Sometime between the aforementioned conflict and around 381 BBY, the Evereni Marda Ro—a former adherent of the Path—tracked them down, as she sought out the few surviving Path members. She fabricated a narrative regarding the Path's end to position herself as central to their beliefs and desires, offering them the choice of joining her band of buccaneers—who would eventually evolve into the Nihil—or ceasing all Path-related activities. Kortanio and Esstrop were among those who opted to join Ro.
Following Kortanio and Esstrop's decision to join Ro, she led them to her vessel, the Gaze Electric, where she revealed a creature that consumed the Living Force, known as the Great Leveler. Ro elucidated that the group's purpose was to safeguard the beast, so that it could one day devour those who misused the Force. She further stated that the group Kortanio had joined lacked a shared religion or a narrative to impart to the galaxy, and their sole objective was survival.
Kortanio and Esstrop rapidly became loyal to Ro, functioning as her most proficient raiders. The pair employed their transport to steal items, which they subsequently returned to the Gaze Electric and presented to Ro with enthusiasm. Kortanio and their partner occasionally collaborated with fellow raiders Milan Stor and Fori Nagor to execute larger-scale raids.
One such assault occurred no earlier than 379 BBY, when they attacked a refugee camp and—due to the refugees' lack of possessions to pilfer—instead abducted the refugees. Upon returning to the Gaze, Nagor presented the refugees to Ro, who was incensed by their actions. Ro commanded Nagor to release the refugees, with the exception of a Force-sensitive green-skinned man whom Ro delivered to the Great Leveler. Subsequently, Kortanio and Esstrop escorted the Evereni twins, Vika and Velya Faer, to the throne hall of the Gaze Electric after the Faers accepted an invitation from Ro for a meeting.
Later, Ro discussed Kortanio in a communication she recorded for her descendants, emphasizing the significance of preserving their name. By 252 BBY, during his formative years, Ro's great-great-grandson Marchion Ro had listened to her journal, including the entries mentioning Kortanio.
Kortanio and Esstrop possessed a shuttle used for transportation while serving both the Path and later Ro.
Kortanio made an appearance in a flashback within the short story "A Closed Fist Has No Claws," penned by Tessa Gratton and featured in the 2023 young-adult anthology The High Republic: Tales of Light and Life as part of the Star Wars: The High Republic multimedia initiative.