The Ossus Massacre, which is also referenced as the Fall of Ossus, Massacre on Ossus, Attack on Ossus, Assault on Ossus, or simply the Ossus massacre, designates a battle that unfolded in 130 ABY, a mere two days after Coruscant succumbed. The seizure of that galactic capital planet compelled the Galactic Federation of Free Alliances to yield to the Fel Empire's might. This event seemingly restored unified governance to the galaxy. However, Darth Krayt manipulated events, orchestrating a coup d'etat to seize control of the Empire and proclaim himself Emperor. Krayt believed that eliminating any potential opposition was crucial for his coup's success. Therefore, he concluded that the New Jedi Order needed to be eradicated. With the Galactic Federation of Free Alliances already defeated, the Jedi would be his only remaining obstacle upon becoming Emperor.
The initial purpose of the Ossus mission was a simple diplomatic meeting between the Jedi and the Empire to strengthen their ties and maybe even form an alliance. However, Darth Krayt intervened and ordered the Imperial forces to attack the Jedi, turning the meeting into a massacre that began the Third Jedi Purge. Fortunately for Darth Krayt, only half of the order was present, since the others had left for other planets after the fall of Coruscant, and he had not waited for all of them to gather at Ossus.
The Ossus Massacre was the site of many Jedi deaths at the hands of the Sith forces. Darth Krayt's assault achieved its goal, and among the casualties was Jedi Grand Master Kol Skywalker, who valiantly resisted the overwhelming Sith forces to safeguard the younglings. Master Wolf Sazen aided Kol and was defeated by Darth Nihl, but he survived thanks to Kol's son. Although many were killed, several Padawans and younglings managed to escape in J-1 shuttles. Many Sith and Stormtroopers were also killed during the Massacre. Many Yuuzhan Vong warriors and shapers, there because of their terraforming activities, were also executed.
Following the Sith–Imperial War's conclusion, much of the Galactic Alliance surrendered to the Fel Empire, integrating into the latter's galactic government. However, the reigning Emperor, Roan Fel, understood that while the Alliance had capitulated, the Jedi would remain loyal to the Force and would not pledge allegiance to any individual. The Empire had grown stronger with the Sith's support, and Fel knew the Jedi would never align with an Empire that had allied with the users of the dark side of the Force. Nevertheless, he valued their capabilities and did not want to emulate previous Imperial rulers, knowing that the Empire had previously destroyed the Jedi Order and not wanting it to do so again.
As expected, the New Jedi Order refused the Emperor's demand for surrender, with half retreating to the Jedi Academy on Ossus and the rest dispersing across the galaxy. Some Jedi joined the Empire, becoming Imperial Knights. Two days after the Alliance's fall, an Imperial task force under Moff Rulf Yage was sent to Ossus. Fel's intention was for this to be a diplomatic mission, aimed at persuading the Jedi to ally with the Empire, similar to the Imperial Knights. He explicitly forbade Yage's troops from initiating hostilities under any circumstances.
However, Fel did not anticipate the Sith's intervention at this critical juncture for the Empire and the Jedi Order. Their leader, Darth Krayt, who had known the Jedi for over a century, understood that even if they agreed to work with Fel, they would never accept Krayt's vision for the galaxy. He planned to seize Fel's Empire for himself. The Jedi would never accept a Sith as Emperor after the damage past Sith rulers had done, so if his vision of order was to be fulfilled, the Jedi had to be eradicated. His agent, Darth Maladi, contacted Grand Admiral Morlish Veed with direct instructions from him: Yage's forces were to attack and destroy the Ossus academy alongside forces Krayt would be sending to assist. Lest he be embarrassed later, Veed agreed to countermand Fel's order and make it look like his own idea.
The combined Sith and Imperial assault, led by Fist Darth Nihl and Yage, respectively, inflicted severe damage on the Jedi Order and the planet's ecosystem. Numerous Jedi perished, along with many Yuuzhan Vong warriors and shapers who were present because the Galactic Alliance and the New Jedi Order permitted their Shapers to use a desolate portion of Ossus as a test site for terraforming. Kol Skywalker, recognizing the Jedi's disadvantage, chose to fight alone to delay the joint Sith and Imperial force, allowing his son Cade Skywalker and several younglings to escape into hyperspace on various J-1 shuttles. Kol was supported by Cade's Master, Wolf Sazen, who fought Darth Nihl.
Cade Skywalker could not simply watch his father die at the hands of the Sith. Ignoring his father's instructions to flee, Cade left his charges' shuttle and fought by his father's side. Meanwhile, Master Sazen was overpowered by Darth Nihl, who cleaved off Sazen's right arm and used the Force to hurl him back behind Kol. Kol reasoned with Cade and was able to convince him to take Sazen to the ship because of his injuries. Obeying his father, Cade boarded the last Jedi shuttle to leave Ossus.
Meanwhile, Kol stood alone against the much larger numbers of the advancing enemy force. Though he was able to inflict a large number of casualties, he was eventually felled by Darth Nihl. However, Cade, upon sensing his father's death through the Force, took a X-83 TwinTail starfighter docked in the shuttle he was aboard and attempted to make his way back to Ossus. In the ensuing dogfight with a number of enemy Predator-class fighters, Cade's X-wing starfighter was blown to pieces and Cade was apparently killed. However, he managed to escape by sealing his flight suit and jettisoning just as the ship exploded.
Another Jedi apprentice, Ellu Viss, was able to take a book detailing the history of the Force, Jedi vs. Sith: The Essential Guide to the Force by Jedi Master Tionne Solusar 90 years before, when he successfully fled the Temple. He resolved to find any other surviving Jedi he could so they could unite and use information therein to try to figure out how to bring down the Sith.
While the Sith and Imperial forces also suffered losses, the attack did not achieve Krayt's goal of total annihilation. Because they had not waited until all the Jedi had returned to Ossus, more than half of the order was elsewhere during the attack and remained at large. The survivors of the Order would go into hiding throughout the galaxy, with many members taking refuge in a Hidden Jedi Temple on the planet Taivas. Those who did not find themselves there, a large number since the Temple was a secret from most Jedi before the Massacre, were hunted by bounty hunters seeking to give them over to the Sith. Darth Maladi kept a list of all active Jedi and determined what large purse each was worth.
The massacre also prompted the Sith to openly challenge Emperor Fel. Fel's anger at having his specific orders disobeyed moved him to assemble the Moff Council in special session to deal with Veed—as well as his lover, Moff Nyna Calixte. Krayt understood that Fel was no longer of use so, before Fel could act, Krayt launched a palace revolution to oust Fel and place himself on the throne, the first Sith Lord to rule the majority of the galaxy since the reign of Darth Caedus almost a century earlier. Calixte, secretly Kol's wife and Cade's mother, was devastated when she learned of the Massacre on Ossus and heard that they both died. She lost her faith in the Empire after it was taken over by the Sith, and she endeavored to stay inside to advance her own purposes.
The Sith used propaganda to portray the raid as a justified action against traitorous Jedi in the public's eye. Because the war began over the sabotaged Ossus Project that killed many and ruined entire worlds, the Jedi were blamed for dragging the Galactic Alliance with them to war against the Empire when they came to the defense of the Yuuzhan Vong terraformers who had used the opportunity to plot the project's "failure." Moff Yage was named the "Hero of Ossus" by the people though he never called himself such, and his detractors took to calling him the "Butcher of Ossus." He sank into a deep depression following that day's events and drank heavily for a week to escape them, ashamed that he'd been used by the Sith in their plot to take over the galaxy, but he resigned himself to the fact that he would not be able to take back what he did. When people who knew the truth of the Sith sabotage spoke out, they were quickly dismissed and written off for believing the propaganda of the defeated Alliance and the lies of the fallen Jedi.
In 137 ABY, Cade Skywalker returned to Ossus and he experienced several visions of his ancestral family members such as Mara Jade Skywalker and Anakin Skywalker brought on by a Death sticks binge. There he met Jedi Master K'Kruhk, who cleansed Cade's body of the death sticks' impurities, as well as his former Master Wolf Sazen and Shado Vao, Kol's Padawan, who had recently returned to Ossus expecting to find him. During a sparring session, Skywalker and Shado discovered a secret floor of the Temple, discovering Vong shaper Nei Rin guarding a lost vault of Jedi artifacts with her assistants.
Skywalker eventually left the Temple for Coruscant after having a vision of Hosk Trey'lis being tortured in the Sith Temple, while the other Jedi and the Vong stayed behind. Since the massacre, Krayt's Empire had conducted periodic searches of the Temple, to catch any stray Jedi that may have returned. Darth Stryfe, a Sith Lord of the One Sith, was dispatched to the world with stormtroopers to conduct one such scan. Some Stormtroopers conducted a search of the surface at Stryfe's order, nearly catching the Jedi, before Sazen clouded their minds and sent them away. Stryfe felt this use of the Force and ordered the search to continue, though it remained fruitless. Stryfe, still feeling the Jedi presence, ordered the destruction of the Temple as a means to eliminate the potential threat. His vessel opened fire, leveling the building. He failed, and the Jedi inside survived. The Jedi at the Hidden Temple would later send a delegation to work with the Galactic Alliance Remnant and the Fel Empire in their war against the Sith because of this action.
Although the Massacre itself only appeared in the first and eighth issues of the Legacy comics, it was often used as a flashback point for Cade, signifying the major impact it had on him and the series. In the opening issue, the Massarce was pencilled by Jan Duursema, inked by Dan Parsons and colored by Brad Anderson. The eighth issue was illustrated by Adam DeKraker and colored by Ronda Pattison. It also garnered an appearance in Jedi vs. Sith: The Essential Guide to the Force, in which it was not mentioned as "Massacre at Ossus" but is included.