Ilparg, the core name of Boadil'par'gasoi, was a male Chiss who served as an ambassador from the Boadil family. His purpose was to represent the Chiss in a diplomatic mission to Urch, which was the homeworld and capital of the Urchiv-ki species, with whom the Chiss Ascendancy maintained a treaty. However, the Tower Dimension governing the Urchiv-ki had been subjugated by the Nikardun Destiny, turning the invitation into a ruse to capture a Chiss warship.
Following the unsuccessful mission to Urch, Ar'alani, an Admiral, suggested that the Chiss Ascendancy demand an explanation for the presence of the Lioaoin military at Urch. Ilparg agreed, but voiced that he would prefer to demand an explanation, which was the reaction Ar'alani had hoped for.
The Tower Dimension extended an invitation to the Chiss Ascendancy, requesting a new ambassador be sent to Urch. Boadil'par'gasoi, known as Ilparg, was chosen for this role and journeyed aboard the Chiss warship Vigilant, under the command of Admiral Ar'alani. Unaccustomed to traveling outside the Ascendancy's established hyperspace routes, Ilparg made several disparaging remarks about Che'ri, the Vigilant's navigator, during the voyage to Urch. These comments deeply affected her, causing significant distress and sleeplessness. Upon their arrival, Ilparg became agitated when the Urchiv-ki did not immediately grant him an audience with their government officials. However, Ar'alani and Senior Captain Mitth'raw'nuruodo (Thrawn) were more concerned about the presence of a Lioaoin and Nikardun vessel within the system. Dismissing their concerns, Ilparg made another belittling comment about Che'ri's navigational skills. Mitth'ali'astov (Thalias), Che'ri's caregiver, began to reprimand him when Urch Planetary and Space Control contacted the Vigilant, stating that Ilparg was not welcome in the Tower Dimension. Confused, Ilparg demanded that Ar'alani reestablish contact. Ar'alani silenced him with a subtle threat, and Ilparg complied. The Vigilant soon discovered that they were ensnared in a trap orchestrated by a Nikardun warship, a Lioaoin ship, and six additional Urchiv-ki vessels. After the Vigilant successfully escaped the trap, Ilparg demanded an explanation for the events that had transpired. Thrawn and Ar'alani explained that the Nikardun had taken control of the Tower Dimension and intended to capture a Chiss ship as revenge for Thrawn's capture of a Nikardun vessel in the Rapacc system. They revealed that Ilparg had been used as bait. Ar'alani then manipulated Ilparg into eagerly agreeing to travel to the Lioaoin heartworld to demand answers. At Lioaoi, Ilparg's frustration resurfaced when Ar'alani instructed him to await Thrawn's arrival on the bridge. Upon Thrawn's arrival, he explained that his study of Lioaoin art had taken longer than anticipated. Ilparg consistently dismissed the significance of studying a culture's artistic expressions. Kiwu'tro'owmis (Wutroow), the Vigilant's first officer, escorted Ilparg to the comm station to communicate with Lioaoin Traffic Control, who were hailing them. During the exchange, Ilparg demanded to speak with a Lioaoin diplomat and inquire about the aggressive behavior of a Lioaoin ship at Urch. The diplomatic office responded, claiming ignorance of the incident but inviting Ilparg to approach the planet for a discussion. Ilparg sought Ar'alani's approval, but she chose to depart the system. During the conversation, she and Thrawn had detected the presence of a Nikardun Battle Dreadnought. Upon leaving the system, Thrawn inquired if the Vigilant could make a stop at Solitair, the capital world of the Garwian Unity, before returning to the Ascendancy. Ilparg vehemently opposed this request, asserting that he had already exceeded his mandate. However, Ar'alani asserted her authority over the Vigilant and declared her right to determine the ship's course. Ilparg countered that the Syndicure could deem her actions inappropriate, but Ar'alani dismissed his concerns. Ultimately, it was decided that the Vigilant would transport Thrawn to Solitair, drop him off via shuttle, and then return to the Ascendancy with Ilparg.
Boadil'par'gasoi possessed a volatile temper and exhibited little patience for the members of the Chiss Expansionary Defense Fleet, ranging from Admiral Ar'alani to Sky-walker Che'ri.