Che'ri was a Force-sensitive Chiss female who served as an ozyly-esehembo within the Chiss Ascendancy. Thalias was her caregiver, or "Momish" while she served on Mitth'raw'nuruodo's ship. She liked to draw on her questis and later with colored graph markers. She often drew pictures of birds, flashflies, and scenery as seen from above, as she had always dreamed of flying. Che'ri often had nightmares, which was typical of sky-walkers. She understood the trade language of Meese Caulf.
Che'ri was born around 29 BBY. At a young age, she was determined to have Third Sight, and was made part of the Chiss Sky-walker corps.
She served on multiple ships, with eight caregivers, until she fell under service to Mitth'raw'nuruodo, core name "Thrawn," aboard his ship, the Springhawk. Che'ri was sprawled across a chair making drawings/collages of pre-existing assets in her questis when her new caregiver, Mitth'ali'astov ("Thalias") arrived. Instead of introducing herself right away, Thalias, not wanting to overwhelm Che'ri, went to her private quarters to settle in. However, after a while, Thalias introduces herself and compliments Che'ri's artwork, describing it as a talent to be cherished. Che'ri reflects upon how her previous caregivers found her artwork to be "silly". Che'ri is surprised to learn that Thalias had been a sky-walker (with only four caregivers). The two talk about the incompetencies of the operation of the sky-walker/caregiver system. Eventually, Che'ri is concerned about going into a battle, but Thalias tries to soothe her by reassuring Senior Captain Thrawn's military prowess. Thalias asks Che'ri if she would like to read about Thrawn's military career. Che'ri refuses, citing her dislike of reading, but Thalias sends the file to her questis anyway. Che'ri complains about the file being too long, to which Thalias promises to create an abridged version at a later time.
After a battle over the Paataatus Hiveborn homeworld of Nettehi, Che'ri brought the Springhawk out of hyperspace in an unknown system. Che'ri was starting to feel an overload spell, but did not say any anything about it, due to being taught to not show weakness. She silently hoped that Thrawn would allow her to take a break from her duties. To her surprise, Thrawn allowed her to rest. Che'ri, while relieved, was disturbed at the thought of Thrawn knowing of Che'ri's need for a break. Thrawn orders the helm officer, Lieutenant Commander Tumaz'mor'diamir ("Azmordi") to bring the Springhawk into a high orbit over the system's planet. As Azmordi took control of the ship, Che'ri became fascinated with the ship's controls. Che'ri overheard Thalias thanking Thrawn for stopping the ship, recognizing that she too knew of Che'ri's coming overload spell. She wondered if everybody knew.
Thalias offered to help Che'ri back to the suite, to which she declined; Che'ri did not want to be carried. When Thrawn expressed concern for Che'ri, Thalias discussed overload spells and asked if Che'ri could stay on the bridge for a bit of time to start her recovery process. Che'ri was comforted by Thalias's understanding and acceptance of her overload spells, as previous caregivers did not understand and would sometimes get angry with Che'ri over them. Thrawn stated that he was not surprised that Che'ri was being strongly affected by their current location. Che'ri, curious, tried to see what Thrawn was talking about by looking at the planet through the Springhawks viewport. Thrawn, now standing very close to Che'ri, instead pointed her to observe one of the bridge displays. Che'ri was surprised at Thrawn's willingness to talk directly to her. She looked at the display and was surprised to see a quadruple-star system. Thrawn theorized that entering a system with four stars took an extra toll on Third Sight, and Thalias agreed.
Thalias asked Thrawn about the purpose of their current mission. Thrawn shared the plans to investigate the origin of the refugee ship found derelict in the Chiss Ascendancy's Dioya system. Despite objections from Azmordi, Thrawn explained that it is important for Thalias and Che'ri to know about their ship's mission, calling them a part of the "team". This surprised Che'ri (she had always thought of herself as "just the sky-walker" and her caregiver as "just her momish").
After some more discussion, Che'ri felt well enough to leave with Thalias to their quarters. On the way to their suite, they discussed Thalias's own overload spells. Thalias recounted that she had only ever had to deal with a triple-star system and praised Che'ri for being able to handle a quadruple-star system. Thalias then drew Che'ri a bath, fed her, and put her to sleep.
Later, Che'ri told Thalias that she had a nightmare. Thalias told her that she, too, had nightmares as a sky-walker. This motivated Che'ri to discuss her nightmare with Thalias in further detail. Che'ri's nightmare included the feeling of being lost, the feeling of everyone looking at her but not speaking with her, and the feeling of being stuck in a soap bubble. Thalias explained that the soap bubble aspect had come from her previous bath. She elaborated by stating that Che'ri's brain had taken the soothing bubbles from the bath and combined them with her fears of getting lost and no one paying attention to her. This eased Che'ri discomfort, and she asked Thalias if she had ever gotten lost in space, to which Thalias responded that she had only gotten lost when her Third Sight abilities had begun to fade. Thalias told Che'ri that tests of sky-walker abilities were done within the safe and defined hyperspace lanes between the core Chiss worlds; if something were to go wrong, there would be no danger to the ship. When Che'ri continued to express fear of getting lost, Thalias told Che'ri to trust in her abilities.
Upon the Springhawk reaching its next destination, Rapacc, Che'ri was transported aboard Admiral Ar'alani's ship, the Vigilant, due to fears over her safety if the Springhawk was compromised during an upcoming mission. Che'ri was spending time with the Vigilants eight-year-old sky-walker Ab'begh and her caregiver, playing with Ab'begh's colored graph markers and building snaps. The caregiver interrupted them, insisting that they read for a little while. Despite being upset, she obeyed the caregiver due to fears of Ab'begh being punished later for Che'ri's own disobedience. Ar'alani arrived to share the news of the Springhawks safe status with Che'ri. She told Che'ri that she would have to spend the night on the Vigilant. Che'ri asked Ar'alani to clarify that Thalias was aboard the Springhawk, to which Ar'alani confirmed. Ar'alani also notified Che'ri that she would have an extra bed brought in for her. Ab'begh offered to share her bed with Che'ri, but Che'ri, cringing, refused. To try to comfort Ab'begh's obvious offense at her refusal, Che'ri clarified that she kicks in her sleep. Ab'begh then asked Che'ri to bring her bed into her room, stating that she sometimes got scared at night. Che'ri accepted the proposal, adding that they could take some figures with them to play with before they slept. Ab'begh's caregiver and Ar'alani approved, with the stipulation that the girls promised to get some rest. When Ar'alani left the suite, the caregiver told the girls that they have to read for half an hour, and Ab'begh offered Che'ri to read a picture book with her. Che'ri cringed again and refused, stating that she had something else she was supposed to read. Ab'begh continued to attempt to get Che'ri to read with her, but Che'ri refused and reminded her that they could get back to their building snaps if they finished their reading as soon as possible. Ab'begh agrees and starts to read her picture book. Che'ri picks up her own questis, reflecting on the fact that some of her previous momishes would not allow her to have graph markers. She decided that once she saw Thalias again, she would ask her to get some graph markers, hoping to do some real artwork with them. Che'ri found and pulled up, on her questis, the file on Thrawn that Thalias had sent her. Thalias had forgotten her promise to make an abridged version of the file, but Che'ri decided to read the file anyway because Thalias thought it would help her with her fears for the Springhawks safety. Thalias's mission would reveal the existence of the Nikardun, led by General Yiv the Benevolent.
Upon the Springhawks return to the Ascendancy, Che'ri and Thalias were temporarily transferred to the Vigilant due to the Springhawk needing repairs. They were to navigate Ambassador Boadil'par'gasoi ("Ilparg") to the Tower Dimension capital of Urch. During the journey, Ilparg made several derogatory statements within earshot of Che'ri, which upset her. On one night, it took everything Thalias had to get Che'ri to sleep. Before arriving at Urch, the Vigilant took a hyperspace detour that delayed them multiple hours. Ilparg was once again upset and later made another derogatory comment about Che'ri's navigational abilities. It became apparent that the Vigilant was about to be trapped by the Nikardun, the Lioaoi, and the Urchiv-ki. The Vigilants first officer, Senior Captain Kiwu'tro'owmis ("Wutroow"), described the enemy's net formation as a mirror payback maneuver. Che'ri asked Thalias what that meant, but Thalias did not know. Thrawn, however, described the maneuver to them. Che'ri became anxious about her safety, and Ar'alani tried to soothe her. Ar'alani and Thrawn prompted Che'ri to point out an optimal escape vector, and when Che'ri provided it to them, the Vigilant had to perform a risky maneuver to escape the mirror payback. When the Vigilant escaped the enemy's reach, Che'ri was instructed to enter hyperspace. Before she did so, she asked Ar'alani how far she wanted to go. Ar'alani told her to go as far as she could until she needed a rest period.
It was decided that the Vigilant would head to the Lioaoin heartworld to demand answers for what occurred at Urch. During this visit, it was learned that the Lioaoin Regime had become allies of the Nikardun. After leaving the system, Che'ri was awoken by Thalias and was ordered to reroute the Vigilant to the Garwian Unity capital world of Solitair.
Upon arrival at Solitair, Thalias informed Che'ri that she would be departing on a mission. Che'ri did not take this well. She asked Thalias to get her some graph markers, but Thalias did not have any and could not get any before she departed. Che'ri exclaimed that she hated Thalias. Thalias had chosen Ar'alani as Che'ri’s temporary caregiver while she was gone. When Ar'alani initially arrived at the sky-walker suite to check up on Che'ri, she refused to leave her room. Later, after she came out of her quarters, Ar'alani asked Che'ri if she was upset that Thalias left her. Che'ri's lip quivered, and she told Ar'alani that Thalias hadn't even told her why she was leaving. Ar'alani attempted to soothe her by saying that she too had always hated adults not telling the whole story. When Che'ri expressed worry about Thalias's safety, Ar'alani nonchalantly stated that there was danger everywhere, not realizing that this was one of the worst things she could have said at this moment. Che'ri started to sob, proclaiming that Thalias was going to die. Che'ri regretted yelling at Thalias. Ar'alani attempted to soothe her again, which had little success. When Ar'alani left to draw Che'ri a bath, the girl asked her to tell her about some of the missions she had with Thrawn. Che'ri recounted how the file that Thalias sent her was too wordy and that she could not read well.
After returning to the Ascendancy, Che'ri guided the Vigilant to Primea, where it extracted Thrawn and Thalias. The Chiss stole a Vak patrol craft in their escape. On this mission, the wife of Syndic Irizi'stal'mustro ("Zistalmu"), who referred to herself as “Nana”, acted as Che’ri’s temporary caregiver. However, four Lioaoin cruisers attacked the Chiss there. The Springhawk, now finished with its repairs, and the Vigilant were sent to the Lioaoin heartworld to retaliate, and Che'ri and Thalias were returned to their stations aboard the Springhawk. At the Lioaoin heartworld, a battle between the Lioaoi and the Chiss began after Che'ri and Thalias returned to their sky-walker suite. Che'ri heard several impacts along the outside hull of the Springhawk, which scared her. Thalias explained to her that the impacts were likely from pieces of shrapnel from destroyed enemy missiles. Che'ri expressed worry that the acid from breacher missiles would be headed for the Springhawk, but Thalias explained that the Chiss were the only ones who used breachers. Che'ri asked why no one had ever revealed this kind of information to her before, and Thalias explained that caregivers are likely not allowed to. Thalias believed that Che'ri knowing about this kind of military information may give her a sense of comfort. Che'ri, upon learning that certain things aren't allowed to be revealed to her, complained about being treated like a child, but Thalias complimented her for her bravery and resilience, stating that she had undergone more stress than most Chiss would ever experience in their lifetimes.
After returning to the Ascendancy, Che'ri and Thalias were asked by Thrawn to accompany him on a mission of unspecified purpose and duration. They agreed, but before they could leave, Thalias needed to catch up with another important task. Thrawn learned this and asked Che'ri if she was comfortable joining him on the mission alone. Che'ri contemplated the ramifications of going with Thrawn alone but ultimately accepted his proposition. She embarrassingly asked Thrawn to get some more colored graph markers for the trip, but, to her surprise, Thrawn had already bought two boxes of markers and four binders of paper to draw on.
As they departed, Che'ri became anxious and wished for any of her caregivers to be present (even the ones she hated). Thrawn, noticing her troubled nature, attempted to soothe her. Eventually, he correctly guessed that she would like to become a pilot after her tenure as sky-walker. Che'ri, surprised, asked Thrawn how he knew that. Thrawn stated that he could tell from her drawing of birds, flashflies, and top-down landscapes. Thrawn offered Che'ri to take the pilot controls, and, after some thought, Che'ri reluctantly took them. Throughout their journey to the eastern edge of the Chaos, towards Lesser Space, Thrawn gave Che'ri many lessons on flying, and, notably, Che'ri had dreams of flying that weren't nightmares for the first time in her life.
Over the course of the next several weeks, Che'ri learned to fly. When they reached Lesser Space, Thrawn and Che'ri explored five worlds: Batuu (where a small patrol force was staged), Umme, Yakorki, Ovanis, and Mokivj (where a highly advanced energy shield was detected). Additionally, at Mokivj, the Chiss encountered another ship. The other ship would go into hyperspace, and Thrawn commanded Che'ri to follow it to the first system: Batuu. Che'ri did not believe in her ability to get to Batuu before the other ship did, but, nonetheless, when the Chiss arrived, they were ahead of the other ship. Thrawn communicated with the other ship in Meese Caulf. The Chiss witnessed the ship go to the surface, and, a couple of days later, they witnessed another ship descend to the same place. A couple of hours later, the first ship would escape the system, but the second did not follow. Several days/weeks later, another ship arrived at the system, belonging to the Jedi General Anakin Skywalker of the Galactic Republic. General Skywalker told the Chiss to go on their way. Thrawn noted to Che'ri the coincidence of the general's last name, hinting at the name's similarity to the Chiss sky-walker. Thrawn asked him what he was doing in this part of the galaxy, but Skywalker responded by stating that it was none of his business. Thrawn personally asked Che'ri if she thought Anakin would make a good ally. Che'ri, sensing strength, commitment, and confidence, affirmed. Thrawn offered Skywalker help on his quest, noting that he knew of the location of the second ship. The two agreed on an alliance, and Thrawn identified himself as Commander Mitth'raw'nuruodo, instead of Senior Captain, much to Che'ri puzzlement. He also proposed that Skywalker refer to him by his core name, but, much to Che'ri's enjoyment, Skywalker stubbornly refused, repeatedly mispronouncing Thrawn's full name before accepting the use of the core name. Before departing, Thrawn asked Che'ri if she was comfortable operating the ship by herself. Che'ri realized that, if she said no, Thrawn would be completely willing to call off his current alliance with Skywalker. However, Che'ri affirmed to Thrawn that she could handle the ship. Thrawn instructed her to return to Mokivj, wait on his signal, and utilize decoys to distract any enemies he may run into. Che'ri asked Thrawn if he was going to be okay, to which Thrawn affirmed, stating that he believed Skywalker would be a powerful ally.
During an assault on a Separatist droid factory, Che'ri launched decoys in order to land within a factory and help Thrawn retrieve a shield generator that had been protecting the factory.
Almost five weeks after they departed from the Ascendancy, Thrawn and Che'ri returned, where they met with Thalias and Ar'alani to discuss the next course of action in dealing with the Nikardun threat. Notably, Che'ri would raise a question concerning whether Yiv would stay on Primea after a potential defeat. After Ar'alani agreed to Thrawn's plan, Che'ri and Thalias were prepped to return the stolen patrol craft to the Vaks. Che'ri was specifically taught how to fly the ship. Before departing, Che'ri and Thalias were disguised as Chiss "family hostages" by use of heavy plaster makeup. Hidden within this makeup was tava mist, a gas that severely disorients the inhaler. Upon arriving at Primea, Che'ri is successfully able to alleviate Thalias's distrust in her abilities to carry out such an important mission by telling her about her ability to learn how to fly and her own initial distrust of herself. Thalias told the Vaks that the Chiss intended to return the stolen patrol craft and that she had brought a written explanation from Senior Captain Thrawn. The Vaks allowed the Chiss to land, and Che'ri guided the ship toward the navigation beacon guiding them to the landing zone. Upon landing, Thalias and Che'ri were greeted by Vak warriors, who took their message. The Vak told the Chiss that a Navigator would take them back to the Ascendancy, but the navigator turns out to be Qilori, a Pathfinder aligned with Yiv, who takes them directly to Yiv's ship, the Battle Dreadnought Deathless.
Yiv subsequently captured Thalias and Che'ri, seemingly believing their status as hostages. While they waited, Che'ri was notably shaken by Yiv's show of confidence. After Thrawn arrived and was tractored by the Deathless, Che'ri and Thalias stripped away their makeup, releasing the tava mist and disorienting their Nikardun captors. Because of this, Thrawn was able to successfully capture Yiv and rescue Che'ri and Thalias from the Nikardun.
Later, Thrawn met with Thalias and Che'ri to discuss the outcome of the battle at Primea. During the conversation, Thrawn called Thalias a Trial-born of the Mitth. This was the first time Che'ri had heard about Thalias passing the Mitth Trials, and she congratulated her.
During the missions to defeat the remaining Nikardun, Che'ri navigated the Springhawk back to Rapacc, where Thrawn checked on the status of the Nikardun in that system. Before arriving, Che'ri discussed many things with Thalias, now her official caregiver. Che'ri asked Thalias what the Paccosh were like, and Thalias described their appearance to her. They also discuss the fallout Thrawn received when he taught Che'ri how to fly the scout ship on their mission to Lesser Space. Thalias also expresses her apologies for missing Che'ri's tenth starday, wanting to make it up to her. Finally, Che'ri informed Thalias of Thrawn's arrival on the bridge one-and-a-half seconds before Thrawn actually opened the bridge hatch.
On a mission to the planet known to the Chiss as Sunrise, Che'ri was brought out of Third Sight seventy minutes before her previous break. Thalias was experimenting with bringing the girl out of Third Sight in alignment with the girl's natural sleep cycles, hoping that it would help improve her mental health. This method seemed to work after the first two attempts, and Thalias hoped to make the strategy standard for the Springhawk. Upon arriving at Sunrise, Che'ri was stationed in the Springhawks secondary command in case she was needed for a quick escape. There, she would watch Azmordi make an in-system jump toward the planet. Thalias asked Che'ri if she had been taught by Thrawn how to do an in-system jump. Che'ri stated that Thrawn taught her and that she did a mediocre job. On the other hand, Che'ri was amazed at the precision Azmordi showed in his jump.
On the mission to Sunrise, Thrawn was taking the Magys and her companion, the leader of a refugee group originating from this world, to see if there were any survivors of the civil war that happened there. On their way back to the Ascendancy, Che'ri witnessed something being put into Thalias's room in the sky-walker suite. Later, Che'ri, sensing when Thalias was about to leave her room using Third Sight, positioned herself to look into the room. As Thalias opened the hatch, Che'ri saw the object and demanded to know what it was. Thalias reluctantly told her that it was a hibernation chamber containing the Magys and explained that, since the Magys believed her world to be lost, she was going to kill herself and order the rest of the refugees to also do so. Che'ri, shocked, deduced that the Magys's companion was already dead, to which Thalias confirmed. Thalias would also make Che'ri promise not to tell anyone about this matter, as only she, Thrawn, and Samakro were supposed to know.
In a battle above the world of Hoxim, Che'ri received an urgent summon to the Springhawks bridge, where, upon arriving, she would be led to the weapons station instead of the navigation station. Thrawn would instruct her to watch, using Third Sight, a fleeing freighter being tractored by the Springhawks weapons officer, Senior Commander Chaf'pri'uhme ("Afpriuh"). She is to inform him whenever she sees the freighter rotate in Third Sight, as if she doesn't, the continued tractor beam would cause the freighter to twitch, which would cause the analysts on Naporar to conclude that the Springhawk was tractoring it. Thalias objected to this, stating that Che'ri's Third Sight abilities could not possibly allow her to do this, but Che'ri, trusting Thrawn's judgment, agreed to the task. She successfully completed her task, and the freighter was moved at the needed angle. Afterward, Che'ri was brought out of Third Sight, and Thrawn ordered her to be taken to the medcenter for an examination.