Vance Rego served as a member of the Cilpari Resistance during the events of 4 ABY. His mission was to rendezvous with Winter, the New Republic case officer assigned to Cilpar, to secure assistance in their struggle against the Imperials. Simultaneously, he operated as a double agent, employed by the Imperial Moff of the region, Boren Tascl. Rego betrayed Winter by guiding Tascl's stormtroopers to her whereabouts, subsequently fabricating a story for Elscol Loro, the resistance's leader, claiming he narrowly avoided the ambush himself.
Loro grew more and more wary of his actions, particularly his fixation on retrieving a set of spacetrooper armor. Before the assault on the Moff's headquarters located at Kiidan, she challenged him about his behavior. Rego responded by brandishing a blaster at her, but Groznik intervened, preventing her from being harmed.
Rego, all the while cursing Loro, then attempted to retrieve the spacetrooper armor, intending to leverage its offensive capabilities to bolster the Moff's defenses. However, the helmet was missing from the armor, and a ronk had made it its nest, resulting in Rego suffering a severe bite to his forearm.