An der Seite seines Herrn, dem Geonosianer Poggle, war Sun Fac auch bei allen bedeutenden militärischen Staatsgeschäften dabei. So auch im Jahr 22 VSY als die auf dem Planeten Geonosis ansässige Firma Geonosian Industries den Auftrag erhielt, eine große Droidenarmee für die Konföderation unabhängiger Systeme zu produzieren. Graf Dooku, der Anführer der Konföderation, legte mit seinem Partner Poggle die Verträge auf, die zuvor von Sun Fac auf sämtliche Details überprüft wurden. Als rechte Hand von Poggle erfuhr Sun Fac nur wenig Anerkennung für seine Arbeit. Dennoch genoss er in der streng in Kasten eingeteilten geonosianischen Gesellschaft hohes Ansehen und ein gewisses Maß an politischer Macht.

Sun Fac war ebenfalls in der kurzen Gerichtsverhandlung anwesend, in der Anakin Skywalker und Padmé Naberrie im Jahr 22 VSY auf Geonosis zum Tod verurteilt wurden. Als Vertreter des geonisianischen Erzherzogs wurde Sun Fac die Ehre zuteil, das Todesurteil der beiden zu verkünden. Im Laufe der Exekution, die schließlich durch die Ankunft der Jedi und Klonkrieger in der Schlacht von Geonosis mündete, sollte Sun Fac von der Delta Squad getötet werden. Dabei versuchte er mit einem Jäger der Nantex-Klasse zu fliehen, wobei er noch vor dem Abflug von dem Squad-Mitglied RC-1207 (Sev) mit einem gezielten Schuss in die Luft gejagt wurde. 

Sun Fac served as Archduke Poggle the Lesser's chief lieutenant. His position was evident in his insect-like wings, as well as the tusks at the edge of his mouth. Like most other Geonosian aristocrats, he was ruthless in his management of the wingless lower-caste workers, forcing them to work in harsh conditions regardless of any dangers.

As with most Geonosians, Sun Fac was strong, despite his slender build. His tough exoskeleton protected him from physical assaults and the bouts of radiation that occasionally showered Geonosis. Sun Fac's right eye has either been sealed shut or entirely missing. The large scar across his face suggests his missing eye was due to a battle wound.

Over time, Sun Fac, who ensured that his master's will was executed throughout Geonosis, proved to the Archduke that he was both unusually intelligent and very creative for a Geonosian.

In the events leading to the Clone Wars, he also proved that he was as adaptable as intelligent. He was adept at playing any role required of him. Sun Fac could do it all—from supporting the Archduke to becoming a ruthless executioner.

Prior to the Battle of Geonosis, Sun Fac convicted Anakin Skywalker and Padmé Amidala of espionage, sentencing them to death in the Geonosian execution arena. He was responsible for delivering the verdict of the Geonosian court to the two Humans who had come to Geonosis in an attempt to rescue Obih-Wan Kenobi. The news was delivered to a courtroom filled with Separatist Senators, Trahde Federation officials, Commerce Guild dignitaries, InterGalactic Bankingh Clan members, Corporate Alliance representatives, and Techno Union leaders who looked on while the duo protested their innocence.

When the Grand Army of the Republic invaded Geonosis, Sun Fac somehow didn't go into hiding with the Archduke, his aides and other highranking Geonosians, but tried to escape separately. As he wanted to reach his starfighter in the upper levels of a tower protruding from the hive, he knew he was followed by clone commandos, trying to stop him. He did manage to get in his starfighter, but as the ship lifted from the landing platform, it was shot down by clone commando RC-1207, the sharpshooter of Delta Squad. Sun Fac was killed in the explosion.