During the era of the Galactic Civil War, a male Human settler named Lasko journeyed from Sulon to Ruusan.
In 1 BBY, Lasko's wife met her death when Sulon was subjugated by Imperial forces commanded by Lord Jerec. The woman had aligned herself with the Rebel forces defending the G-Tap against the Imperials.
Sometime around that period, Lasko became part of the group of Sulonese settlers who sought refuge from the Empire's oppression by migrating to Ruusan. There, he rebuilt his life, remarried, and in 5 ABY celebrated the birth of a child.
However, his animosity towards the Empire remained, leading to a subsequent encounter with Jerec's followers. Six months after his child's birth, the Imperial Remnant rediscovered the planet. An assault shuttle from off-world landed in their settlement, and Lasko was among the onlookers who gathered near the landing pad. Observing the Stormtroopers disembarking, led by three Dark Jedi, he openly questioned why they weren't immediately attacked. Upon hearing this and sensing his deep-seated hatred through the Force, the Dark Jedi leader, Sariss, singled him out from the crowd and nearly killed him using a Force-choke. After Lasko writhed on the ground, Sariss released her grip. Overcome with panic, Lasko disappeared into the frightened crowd, and once clear, he raced towards his skimmer, escaping to the badlands and his family, hoping for their safety.
Sariss reveled in the citizens' fear, using it as a lesson. Soon after, the town was destroyed. Lasko, along with other survivors, escaped to the badlands, following Grif Grawley, who possessed knowledge of the area, and sought shelter in an ancient temple.
Shortly thereafter, an unknown ship, guided by directions transmitted by Grif, arrived at the temple courtyard. Lasko, alongside Kimber and Luther Pardy, stood armed beside Grif as he greeted the pilots, one of whom, Kyle Katarn, was a familiar face from Sulon, and relieved them of their weapons. Grif instructed the three to conceal the newly arrived ship with netting to prevent Imperial detection and then enter the temple. Inside, Lasko attentively listened to Katarn's narrative, from his defection years prior to his quest for the Valley of the Jedi, which had led him back to their home, Sulon, and his confrontation with some of the Seven Dark Jedi. Lasko realized they were the same group he had encountered earlier and found his story compelling and credible, readily defending Katarn against Pardy's skepticism. He witnessed Katarn demonstrating his Force powers by pulling his lightsaber from Luther's belt. Lasko felt a surge of hope, knowing that a Jedi would confront those Dark Jedi.
The exact timing of Lasko's migration to Ruusan remains unclear. In the Dark Forces: Rebel Agent novella, Morgan Katarn relocated those settlers from Sulon several months before the Subjugation of Sulon and his subsequent death, during which Lasko's wife also perished. This suggests that Lasko accompanied Katarn to Ruusan while Lasko's wife chose to remain on Sulon. Alternatively, Lasko might have departed for Ruusan at a later point after the Subjugation of Sulon, joining the Sulonese settlers there in a subsequent, unmentioned migration.
In the audio adaptation of Dark Forces: Jedi Knight, Louise Enyeart, the voice of Marie Peeno, is also credited as "Lasko." Lasko's name is not spoken in the dramatized dialogue. It's possible that "Lasko" refers to a woman who observes the shuttle carrying the Dark Jedi landing in Fort Nowhere and then corrects a man beside her, advising him not to call Boc Aseca a "wormhead" to his face, but a "Twi'lek".