Kassav Milliko was a male Weequay who held the position of [Tempest Runner](/article/tempest_runner]. He was one of three such leaders within the Nihil, a pirate group that existed during the High Republic era. He was in command of the corvette known as the New Elite. A vicious and calculating commander, Kassav considered breaking away from the Nihil with his loyal followers on more than one occasion. However, he continued to serve Marchion Ro, the Eye of the Nihil, until Ro betrayed him, resulting in Kassav's Tempest being sacrificed during the Battle of Kur. Klinith Da, another member of the Nihil, hoped that successfully sabotaging the starship called the Steady Wing would earn her a promotion, possibly leading to her reporting directly to Kassav.
Kassav Milliko, a Weequay, was born on the planet Sriluur. Milliko never knew who his parents were, and he suspected that he may have been illegitimate. He eventually joined the Nihil, a band of anarchist marauders, eventually rising to become a [Tempest Runner](/article/tempest_runner] together with Lourna Dee and Pan Eyta. He and his Tempest were known more for their recklessness and thrill-seeking behavior than their intelligence, but they were considered to be more powerful than all the other Tempests combined.
Following the [Great Hyperspace Disaster](/article/great_hyperspace_disaster] in 232 BBY, he and Dee's Tempests assisted Eyta's Tempest in a raid on Ab Dalis, which was largely successful. Eyta hosted a celebration in the [Great Hall of the Nihil](/article/great_hall_of_the_nihil] in No-Space to commemorate the event. Afterward, the Runners and Marchion Ro, the Eye of the Nihil, convened for an important meeting. Ro announced that access to the Paths would be limited until the Galactic Republic ceased their investigation into those responsible for the destruction of the Legacy Run. Milliko reluctantly agreed after his attempt to intimidate Ro into reversing the order failed.
The Nihil began to demand credits from planets in exchange for destroying incoming Emergences. Milliko planned to extort the planet Eriadu with his Storms: Gravhan, Dellex, and Wet Bub. While aboard the New Elite, he attempted to extort Mural Veen, the governor. Although she paid the demanded amount, the Tempest failed to destroy the Emergence, resulting in the destruction of Eriadu's inhabited moon. Veen vowed revenge, and Milliko was shocked by the deaths caused by his failure and the creation of a powerful new enemy. Milliko met again with the Eye and the Runners to discuss the aftermath, as the Republic and Eriadu now had the Nihil in their sights. Ro asserted his dominance by severely beating Milliko. When Milliko tried to retaliate, Ro threw vibro-stars that severed most of Milliko's right hand before he could reach his Blaster pistol. Defeated, Milliko obeyed Ro's order to travel to the Kur Nebula.
While awaiting the Republic's arrival, Milliko began to consider his future with the Nihil. He resolved to desert, planning to start anew with his Tempest in a different part of the galaxy. Milliko shared this plan with his people, but his Storms responded by holding him at blasterpoint. They revealed that Ro had ordered them to kill him if he disobeyed the Eye's command to remain at the Nebula. Despite his growing hatred for Ro, Milliko reluctantly agreed. Soon after, Republic and Jedi forces arrived. The battle commenced, and the odds seemed against him until Milliko received a message. Ro responded to Milliko's request for a Path to escape, but instead questioned him about whether he had killed Ro's father, Asgar. Confused, Milliko received assurance from Ro that it no longer mattered because all the suspects, the Tempest Runners, would share Milliko's fate. Ro had sabotaged the entire Tempest's Path engines, causing much of the Tempest to be destroyed in collisions with Republic ships. Eriadu forces, led by Veen herself, stormed the New Elite after the destruction. Milliko attempted to save himself by offering information about the Nihil, but Veen rejected his offer and killed him.
Marchion Ro lied to the surviving Nihil about the circumstances of Milliko and his Tempest's deaths. He portrayed them as martyrs, using their "sacrifice" to unite the Nihil under his leadership and promising to expand their operations throughout the galaxy and defend their way of life from the Republic and Jedi. The Republic, believing they had destroyed the Nihil with Milliko's demise, naively continued their usual affairs.
Kassav Milliko was a cruel person who perfectly embodied the Nihil's nature. He disregarded their rules and was reckless enough to consider killing Marchion Ro, whose position and knowledge were crucial to the Nihil's success. Milliko was uninterested in strategy, preferring to simply raid with his Tempest and gather loot. He and his Tempest were addicts who would ritually consume drugs like spice and [smash](/article/smash] while listening to wreckpunk before a raid.
However, Milliko's ruthlessness had limits, as demonstrated by his distress over the billions of innocent lives lost when he accidentally destroyed Eriadu's moon. He also cared for and respected his Tempest, always trying to prioritize their best interests. Despite his bloodthirsty nature, Milliko knew when to back down and protect himself, as shown by his retreat after being beaten by Ro and his attempt to negotiate with Veen before his death. He held a cynical view, seeing both the Republic and the Nihil as organizations that primarily benefited those in power. He found anything fancy, like Pan Eyta's demeanor, disgusting and contrary to Nihil values.
Like all Nihil, Kassav Milliko wore a mask to conceal his identity and protect himself from the poisonous gases frequently used by the organization. His mask was a plain sheet of metal with slits for his eyes, nose, and mouth. He wore a fur cape that concealed a blaster pistol, which he was known to be highly skilled with.
Kassav Milliko made his first appearance in the 2021 novel The High Republic: Light of the Jedi, written by Charles Soule as part of the Star Wars: The High Republic publishing initiative. Soule mentioned that Milliko was among the easiest and most enjoyable characters to write. In the 2021 audio drama The High Republic: Tempest Runner, Milliko was voiced by Neil Hellegers.