Flim, a male Human con artist, was central to Moff Vilim Disra's scheme to destroy the New Republic in 19 ABY. This involved him impersonating the Chiss Grand Admiral Mitth'raw'nuruodo "Thrawn," who had died during his campaign against the New Republic. He was a component of Disra's Sinister Triumvirate alongside Imperial Major Grodin Tierce, of the Imperial Remnant.
As Thrawn, Flim instilled fear within the New Republic and interacted with numerous New Republic senators, representatives, and Imperial Remnant military officers. He led the Imperial Starfleet. However, shortly before the planned attack on the New Republic, Supreme Commander Gilad Pellaeon, who doubted Thrawn's resurrection, exposed Flim as a fraud. Consequently, the Sinister Triumvirate disbanded, with Flim relieved that his role as Thrawn had concluded.
In the year 19 ABY, Vilim Disra, who was a member of the Imperial Remnant's governing Council of Moffs, extended a military appointment to Grodin Tierce, a former Royal Guard, soon after a meeting with his fellow Moffs and Imperial Supreme Commander Gilad Pellaeon on the planet Bastion, located in the Outer Rim Territories. To persuade Tierce to accept the position, Disra presented Flim, his accomplice, who was masquerading as the Chiss Grand Admiral known as Thrawn. The scheme hinged on exploiting the Caamas Document Crisis, where Imperial agents disseminated rumors implicating the Bothans in the Caamas massacre that occurred many decades prior. While some Bothans were indeed responsible for the Caamas incident, the spread rumors greatly exaggerated the facts, leading to a military stand-down between factions within the New Republic in orbit around Bothawui. Flim dedicated many hours to studying Thrawn's background to maintain the deception. Even Captain Dorja of the Star Destroyer Relentless (Relentless), an officer who had previously served under Thrawn, was convinced of the impersonation. Soon after forming an alliance with Disra and Tierce, Flim unveiled his true identity to Lando Calrissian and Diamal Senator Porolo Miatamia. Following the revelation to the Senate, chaos ensued. While many dismissed the reports, some, including Han Solo and his wife, High Councilor Leia Organa Solo, were quick to believe them. Few Imperials were informed about Thrawn's supposed "return".
Upon hearing these rumors, Gilad Pellaeon, the Supreme Commander, remained uncertain, recalling Rukh's assassination of his mentor a decade prior. During a visit to Bastion to accuse Moff Disra of treason and other offenses against the Empire, Pellaeon discovered a collection of datacards in Disra's desk while briefly alone in the office. After decrypting them, he later met with Talon Karrde, who provided him with a datacard obtained from Jorj Car'das. These datacards, combined with those taken from Disra, exposed the truth about Flim and Tierce. Aboard Karrde's ship, the Wild Karrde, Pellaeon traveled to Yaga Minor to confront Flim, Disra, and Tierce, who were engaged in battle with the Errant Venture. Pellaeon revealed Flim's imposture, Tierce's status as a clone, and Disra's guilt in numerous crimes, including plotting to overthrow the Supreme Commander and embezzling funds for personal gain. Tierce was killed, and Flim surrendered himself and his "command" without resistance, expressing relief that the charade had ended.
Unlike Thrawn, who was a Chiss, Flim was a Human, or a very similar Near-Human, who relied on blue makeup, hair dye, and vibrant red contact lenses for his disguise. During a meeting on Yaga Minor, he demonstrated to Major Tierce and Moff Disra his ability to quickly remove these lenses.
The work "Red Sky, Blue Flame" incorrectly identifies Flim as Tierce's con man.