Mosara Thiirn was a Human female Rebel technician, and later a field engineer for Hydrospeare Corporation. She began working as a Rebel SpecForce technician, stationed aboard a technical frigate. Thiirn took part in the Battle of Archais, where the Rebel Alliance SpecForces (including Shroud Team and Midnight and Storm Squadrons from Eclipse Team) fought the Imperial forces in the oriental seas of the planet Archais.