The initial mission undertaken by Corran Horn after becoming a Jedi was known as the Mission to Courkrus. His objective in 11 ABY was to instill fear into the Imperial pirates, specifically the Invids located on Courkrus, with the intention of forcing their departure from the planet.
Corran Horn, a Jedi Knight, infiltrated a pirate squadron belonging to Leonia Tavira, the former Moff, on Courkrus, the home of the Khuiumin Survivors. He adopted the identity of Jenos Idanian to locate his wife, who had been kidnapped by Tavira. Under this alias, he participated in various missions alongside the pirates.
While visiting Vlarnya, Corran Horn gained a deeper understanding of the other pirate factions operating there. His goal was to disrupt Tavira's operations by driving these pirates off the planet. After dedicating a week to planning his campaign to terrorize the pirates, he commenced the construction of his own lightsaber. Drawing upon the notes provided by Rostek Horn, he utilized scavenged components to complete its construction in a mere two days.
Simultaneously, Jenos Idanian cultivated an image of being perpetually and amiably drunk, which led people to perceive him as largely harmless.
Corran Horn initiated his campaign of terror one evening while conversing with Jacob Nive at The Crash. After Nive consumed some alcohol, Horn employed a mental illusion to project an image of the deceased Imperial Captain Jacob Nive approaching their table, warning Nive that "Doom is coming to Courkrus." This rumor of a ghostly visitation rapidly spread throughout Vlarnya, causing widespread anxiety.
Shortly thereafter, Horn donned a set of green Jedi robes and began patrolling the streets. He encountered two members of the LazerLords pirate gang attempting to assault a woman and intervened to protect her. News of a lightsaber-wielding Jedi being at large quickly spread across Vlarnya. Over the following nights, he replicated similar feats, incapacitating small groups of pirates. On one occasion, he warned members of the Fastblasters that he would kill the next member of their gang that he encountered. Three days later, the Fastblast departed from Courkrus. On another night, he targeted the Blackstar Pirates, who were operating from a secret stronghold located behind the Mynock Hole cantina. Upon entering the rear area, he discovered a spice den, brothel, bar, and gambling house in operation. Igniting his lightsaber, he stalked through the facility, damaging the bar and jubilee wheel, and warned the pirates of impending doom before departing.
However, the pirates realized that he had not yet killed anyone and began to regain their confidence. Shala, the Hutt leader of one of the gangs, fortified his warehouse base and directed his minions to terrorize the local population, challenging the mysterious Jedi. Horn infiltrated the warehouse den and confronted Shala on his dais, who revealed that he possessed the trigger to a series of laser-flechette mines surrounding Horn. Horn attempted to sever the trigger with the extended blade of his dual-phase lightsaber, but the blade malfunctioned. Shala, startled, dropped the dead-man trigger, activating the mines. Horn utilized the Force to protect himself, absorbing the immense influx of laser energy and flame. He released the remaining absorbed energy in a spectacular illusion, transforming the column of flame into a Jedi wielding a lightsaber of fire, which he projected for all of Vlarnya to witness.
Concurrently, certain groups of Vlarnya's citizens had begun to revolt and attack small groups of pirates. The following night, Horn drove off the remaining members of Shala's group and allowed the populace to plunder the storehouse they had been using as a headquarters. The Fastblasters and Shala's gang had completely disappeared, while the LazerLords, Blackstar Pirates, and Red Nova pirates had experienced significant desertion.
Upon learning of the situation, Tavira traveled to Courkrus and located Horn, who was still posing as Jenos Idanian. She informed him that she suspected Luke Skywalker was the "ghost Jedi". She instructed him to take control of the situation and rally the others against the Jedi. Horn immediately commenced visiting the other groups, bolstering morale, issuing security directives, and conveying Tavira's promise of a successful trap for the Jedi. However, while he was devising a plan to fake his own death at the hands of the Jedi, he was attacked by five Jensaarai whom Tavira had sent to apprehend him.