Sky-walkers were Force-sensitive Chiss navigators who helped the Chiss Ascendancy navigate the dangerous hyperspace conditions present in the Ascendancy's native Unknown Regions of the galaxy. In the main Chiss language Cheunh, sky-walkers were referred to as ozyly-esehembo, with "sky-walker" that term's direct translation into Galactic Basic Standard. Sky-walkers served the Ascendancy's military and diplomatic corps in an organization known as the sky-walker corps, and later the seekers program.
Thrawn, a Chiss, recounted his confusion when meeting the similarly named Anakin Skywalker during the Clone Wars after he had asked Darth Vader to use the Force to navigate the Chimaera. Sky-walkers were Chiss children, almost always females and usually between the ages of seven and fourteen, though former sky-walker Mitth'ali'astov recalled the power sometimes lasted until age fifteen. Additionally, the power could sometimes fade ahead of schedule, as occurred to Thalias herself. She lost her abilities at age thirteen. In one rare case, it could sometimes be retained as old as twenty two.
Ozyly-esehembo were taken away from their birth family at a young age and considered to belong to no Chiss family during their service to the Sky-walker corps. However, many Chiss Ruling Families were eager to adopt former sky-walkers, as this was considered a sign of prestige.
Women who cared for sky-walkers were known as caregivers. One hundred years prior to the Nikardun conquests, all caregivers were once former sky-walkers. By the time of the Nikardun conquests, however, almost no former sky-walkers returned to become caregivers to younger sky-walkers. One exception was Mitth'ali'astov, who served as Che'ri's caregiver. The existence of ozyly-esehembo was a tightly kept secret among the Ascendancy, with only high ranking civilian and military officials being told of their existence. In the case of officers of the Fleet, only bridge officers and higher were told; with those of more junior rank told the lie that the ozyly-esehembo was the captain's daughter.
Sky-walkers used what was called Third Sight to navigate through difficult territory in the Unknown Regions. They significantly shorten the periods of time required to travel, taking only a few days where a jump by jump journey took multiple weeks. All sky-walkers were accompanied by a Caregiver. After their Third Sight faded away, many sky-walkers went on to become merit adoptives of important Chiss families of the Chiss Ascendancy. Sky-walkers were taken from their families to be trained as soon as they were found to possess Third Sight. Kivu'rik'ardok, the older sister of the Chiss officer Mitth'raw'nuruodo, was taken away to be a sky-walker when she was five. Some sky-walker training was done on the Expansionary Fleet Complex on Naporar.
When it was thought that sky-walkers were losing their gift, they would be tested within the Ascendancy. A rarer ability that only some sky-walkers had was a form of telepathy, which the Chiss called Second Sight. Chiss officers and warriors held their sky-walkers dear, and did not take kindly to diplomats and other officials disparaging their navigational skills. In particular, pilots worked very closely with the children and tended to be close with them in part.
Entrusted with the data by Mitth'raw'nuruodo "Thrawn" and Admiral Ar'alani, the human officer Eli N. Vanto was assigned codified information about the sky-walkers to try to uncover the secrets of their powers, with the officers hoping that his research could teach them how Vah'nya retained her abilities up to the age of twenty-two.
In a September 1, 2020 interview with StarWars.com, author Timothy Zahn revealed that his development of the Chiss Sky-walker Corps as a major aspect of Ascendancy society was accidental. He had initially developed the ozyly-esehembo "sky-walkers" as a nod to the name of the Jedi Knight/Sith Lord Anakin Skywalker/Darth Vader for Thrawn: Alliances, not intending it to become a major aspect of Chiss society. However, when he was offered to write the Ascendancy Trilogy of novels detailing Thrawn's origins, he was stuck with the name "sky-walkers." Having established the need for Force-sensitive navigators to travel safely through the Unknown Regions, Zahn expanded the notion to develop the Navigators' Guild and other groups of Force-sensitive navigators in the Chaos. Zahn said he wished to balance development of the Chiss culture and other Chiss characters on one hand, and Thrawn "kicking butt" on the other hand, in the series beginning with Thrawn Ascendancy: Chaos Rising.
- Star Wars: Timelines