In 34 ABY, Poe Dameron, who held the rank of Commander, and Kazuda Xiono embarked on a journey to the Dassal system. This star system had been identified by Xiono during his mission aboard the Colossus, and it appeared the First Order was active there. Accompanied by their respective droids, BB-8 and CB-23, they discovered the sun of the Dassal system had vanished, and all its planets had been hollowed out. On a moon, once inhabited, orbiting the only perfectly-cored planet, Dameron and Xiono came across an abandoned village. They concluded it had been the site of a massacre. A probe droid detected the Resistance members, and its destruction brought Major Elrik Vonreg and his squadron of TIE fighters into the fray. Dameron and Xiono evaded capture by leading their pursuers into the gravity well at the center of the cored-out planet, resulting in the destruction of Vonreg's squadron, and they left believing Vonreg himself had perished. Before Xiono returned to the Colossus platform and Dameron set off on a mission to Jakku, Dameron and Xiono exchanged their droids, with BB-8 returning to Dameron.
In 34 ABY, Kazuda Xiono was enlisted by the Resistance and dispatched as a spy to the Colossus platform on Castilon, as part of a mission. He was accompanied by BB-8, the astromech droid belonging to Commander Poe Dameron. Over the subsequent months, Xiono uncovered evidence of the First Order's keen interest in the platform. They were attempting to persuade Captain Imanuel Doza, the owner of the Colossus, to allow them to establish a garrison on the platform under the guise of protecting it from frequent attacks by pirates. Unknown to Xiono, the First Order had hired these pirates to gain control of the Colossus and use it as a staging area. Ultimately, the First Order succeeded in establishing a permanent presence on the Colossus by kidnapping Doza's daughter, Torra, which enabled them to occupy the platform. Despite this, Xiono continued his spying activities, gathering intelligence, but he was unable to contact the Resistance due to a communications blackout imposed by the First Order on the Colossus.
Xiono and BB-8 discovered intelligence suggesting First Order activity in a star system located in the Unknown Regions, near Castilon. Desperate to reach the Resistance, Xiono constructed a makeshift transmitter in an attempt to bypass the First Order's jamming. However, Jarek Yeager, his employer as a mechanic, was doubtful of its effectiveness. Unbeknownst to Xiono, BB-8, and Yeager, Dameron had returned to Castilon to retrieve BB-8, as General Leia Organa had assigned them a mission to Jakku. Dameron infiltrated the platform and arrived at Yeager's repair shop just as Xiono was attempting to use the transmitter. Xiono, BB-8, and Yeager were all surprised by his arrival, and BB-8 was enthusiastic about returning to the main Resistance. Dameron explained that he had brought CB-23 as a replacement droid, but she was located in his T-70 X-wing starfighter, and leaving the Colossus would be more challenging than entering it. Xiono informed Dameron that he had intelligence to share and, in Yeager's office, presented a stolen holomap showing the locations of First Order fleets, along with recent intelligence about the Dassal system. Dameron, noting that General Organa disliked surprises, suggested they investigate the system, as he had enough time before his departure for Jakku.
Dameron, Xiono, and BB-8 departed the Colossus using a Widowmaker maneuver. Xiono, piloting the Fireball due to his familiarity with the ship, landed it on top of a departing freighter, with BB-8 in the droid socket and Dameron clinging to the outside, as the racer lacked passenger space. Dameron worried that the Fireball's bright paint job would attract the attention of TIE fighter patrols, but they went unnoticed. Once the freighter was sufficiently far from the Colossus, Xiono detached the Fireball. However, the ramshackle ship's engines struggled to start, and the ship nearly crashed into the ocean before Xiono and BB-8 managed to restart them. The Fireball met up with CB-23 in the clouds, and Dameron boarded his X-wing. Xiono expressed concerns about the Fireball, but agreed to proceed with the mission.
Upon arriving in the Dassal system, Dameron immediately noticed, through his instruments, that they were in a star system devoid of a star. CB-23 confirmed that the system's sun had mysteriously disappeared. Xiono was taken aback and, after flying past two shattered planetoids, wondered what could have caused such devastation. Dameron pointed out that the planetoids were strangely intact, leading Xiono to deduce that they had been "cored out." Suspecting the First Order, Xiono speculated that they were after resources, but Dameron countered that the planetoids' cores had been left behind.
Xiono and Dameron encountered another planet, Najra-Va, which had been cored out but was otherwise undamaged. The two pilots decided to investigate by flying down the bore. Xiono was perplexed by the motive behind such an action, and Dameron replied they were about to find out. As they approached some floating debris, Dameron's scanners detected a gravity well, and he instructed Xiono to activate his thrusters and turn around. However, it was too late, and as the two ships were pulled into the gravity well, Dameron advised Xiono to try and weather it out. While Dameron maintained some control over his fighter, Xiono struggled until he heeded Dameron's advice, instructing BB-8 to reroute the Fireball's power to the thrusters. The pilots rode the currents out the other end of the bore and out of the inside of Najra-Va.
Soon after, Xiono picked up a signal from a nearby moon, and Dameron agreed to investigate, noting that the atmosphere was still breathable. They landed their fighters in an abandoned village, with Xiono commenting on the cold as he disembarked. A Spider probe droid, stationed in the village, spotted the Resistance members and spied on them from within the ruins. Dameron handed Xiono a blaster, cautioning him against accidental self-inflicted wounds, and instructed CB-23 to stay with the ships and keep them ready for a quick escape. Xiono observed that the village was old, wondering about its former inhabitants, and Dameron responded that the inhabitants were gone, but it was hard to say for how long. In the dark, Xiono slipped on some ice and accidentally fired his blaster, remarking that the exploration would be easier in daylight.
As the probe droid tailed them, Xiono, Dameron, and BB-8 arrived at the largest structure in the village, a temple that Dameron described as a relic of a bygone age. Xiono, noticing blaster fire marks, remarked that the village must have been attacked. Finding an abandoned tooka doll, Dameron surmised that there had been a massacre, and the perpetrators had aimed to eradicate the villagers. He gave the doll to Xiono, before hearing the probe droid's movements and deducing they were being watched. Xiono was initially distracted by the doll and the atrocity it represented, before he and BB-8 joined Dameron in confronting the droid. When the pilots reached the droid, it hovered over them until Dameron fired at it, whereupon it swooped down and knocked down Xiono, so Dameron fired at it again. The droid deployed several smaller remotes, which Dameron referred to as its "kids". He ordered BB-8 to prevent the "mother" droid from escaping while he dealt with the remotes, so BB-8 fired one of his grappling lines at the droid. Xiono, recovering, offered to help, but was hit in the head again when BB-8 was yanked into the air by the probe droid. The astromech anchored himself to a pillar with another grappling line, leaving him suspended in the air.
Dameron led the remotes among the pillars and shot a couple down while telling BB-8 to hang on. Xiono attempted to fire at the probe droid, but missed, nearly hitting BB-8, so he told the astromech to hold the probe droid still. Dameron asked Xiono which droid he was shooting at, at which point Xiono managed to shoot the probe droid's visual processor, sending it crashing to the ground. Xiono cheered while Dameron destroyed the final remote. Dameron complimented Xiono on being eventually able to hit the correct droid before the three went to examine the probe droid. Xiono wondered what it was and what it was doing on the abandoned moon, but Dameron didn't know. At this point, TIE fighters summoned by the probe droid, led by Major Elrik Vonreg, arrived, causing Xiono to state it was almost certainly a First Order droid.
Dameron realized the droid had sent a distress signal, as Vonreg's strafing of the area caused him, Xiono and BB-8 to take cover. He ordered CB-23 to ready the ships for takeoff. CB-23, piloting Dameron's X-wing, shot down a TIE fighter, causing Xiono to cheer as Dameron ordered him to move. Xiono and BB-8 climbed aboard the Fireball while Dameron hopped into his X-wing. Before taking off, Xiono promised to swap BB-8 with Dameron later. The two ships flew into space, and Dameron told Xiono to follow him into Najra-Va's core. Xiono was initially hesitant before realizing it was an excellent opportunity to shake their pursuers. As they entered the gravity well, Xiono and Dameron rode the current while the TIEs had trouble, two of them colliding with debris. Dameron turned back into the gravity well to take out the remaining TIEs, shooting down two more. The loss of his escort caused Vonreg to retreat, making Dameron assume the pilot had been killed when he returned to Xiono.
On the other side of Najra-Va, at a safe distance from the planet, Dameron ordered Xiono to pull around so they could do a droid swap, which Xiono had briefly forgotten about in the excitement. Xiono said goodbye to BB-8, thanking him for his help, before Xiono and Dameron angled the tops of their fighters toward each other. Dameron told CB-23 that he would see her again soon, and asked her to look after Xiono. BB-8 and CB-23 exited the droid sockets and swapped ships, waving to each other as they passed. Dameron welcomed BB-8 back and told Xiono that, as he had that mission for General Organa to go on, he would have quite the report for her when he was done. Xiono was concerned about how he would sneak back onto the Colossus, but Dameron reassured him that CB-23 would tell him. The two pilots bid farewell to each other before jumping into hyperspace.
It was evening on the Colossus when Xiono returned, surprising his coworkers Tamara Ryvora and Neeku Vozo as they worked on a starship. When Ryvora inquired as to the whereabouts of the Fireball, Xiono told her it was docked below and that he had taken the ship out for a spin, which made her suspicious as the Colossus had been locked down by the First Order. Taken aside by Yeager, Xiono told him that he'd discovered the First Order was capable of much worse than anything he'd imagined before. When Ryvora and Vozo noticed Xiono's new droid, he claimed that BB-8's absence was due to him having left him on Takodana for repairs, and that CB-23 was a temporary replacement. Vozo was saddened, saying he was going to miss his friend, but Ryvora was made even more suspicious. After Xiono left saying he was going to show CB-23 around, Ryvora asked Yeager what was going on, and was not pleased when told it was none of her concern, complaining about being kept in the dark when Xiono was allowed to sneak out and get a new droid. Privately, Xiono suspected that what he'd seen in the Dassal system was an indication that they might be in big trouble.
While repairing damage the Fireball had sustained on the mission, Ryvora, who was unaware of Xiono's status as a spy, noted carbon scoring and, suspicious, asked Xiono outright if he had been in a battle on his last trip off the Colossus. Xiono's unconvincing denial only added to her suspicions that there was something odd going on with him.