Daro'Xen vas Moreh: Quarian Admiral and Geth Researcher

Admiral Daro'Xen vas Moreh was a member of the quarian Admiralty Board, set apart by her keen scientific interest in the geth. Possessed of a clinical intellect untroubled by sentiment, she regarded the synthetics not as enemies but as machines to be studied and, if possible, mastered. Her research would tip the balance toward war and later furnish Commander Shepard with weapons against the geth during the campaign for the homeworld. (Mass Effect 2; Mass Effect 3)

A clinical intellect#

Daro'Xen approached the world as a researcher first and a politician second. By her own account she had performed surgery on her childhood toys without guilt or attachment, and she carried that detachment into adulthood. She held no qualms about experimenting on active geth, reasoning that they were nothing more than machines created to serve their makers. Her peers returned her disdain in kind; she described Zaal'Koris vas Qwib-Qwib as a coward and Han'Gerrel vas Neema as "an aging warship," judging his plans for war foolish and self-destructive even as she pursued her own designs on the geth. (Mass Effect 2)

When Commander Shepard brought the geth Legion before the fleet, Xen was fascinated, first assuming it a simple mech and then marveling that it had chosen a name. She mused aloud about what she might learn from it "under slightly different circumstances," to which Legion replied that it was not available for experimentation, and dismissed her schemes for controlling the geth as unsound. (Mass Effect 2)

Tali's trial and Rael's research#

Xen was one of three admirals to sit in judgment at the treason trial of Tali'Zorah, alongside Zaal'Koris and Han'Gerrel. She had no real interest in the proceedings, calling them "a farce born of fear," yet she understood that the trial's true purpose was to stir the Migrant Fleet toward reclaiming the homeworld. After the trial she sent Shepard a cryptic message revealing she had searched the Alarei herself, lamenting that had the Commander presented Rael'Zorah's research, humanity might have reaped its benefits; instead, she warned, others would only watch as the quarians reclaimed their world and, with it, the largest synthetic army in the galaxy. (Mass Effect 2)

Architect of the geth war#

Xen's corps of research and development produced the means to flood the geth's precise scanning systems with white-noise jamming, handing the quarian fleet a decisive advantage and helping push the Admiralty's vote toward war. She led the Special Projects group through the conflict and took pride in the technology that first drove the geth back, preferring open war to Raan's caution or Koris's sympathies, until Reaper involvement turned the tables on her people. (Mass Effect 3)

She continued to craft anti-synthetic countermeasures throughout the campaign, and where Tali was absent she lent Shepard direct support, providing electronic warfare aboard the geth dreadnought and pressing weapons such as the Arc Pistol into the Commander's hands. Her laser-marking work became the Sync Laser that proved critical during the assault on the Reaper base on Rannoch. To the end she eyed the geth as specimens, expressing interest in dissecting Legion after the dreadnought mission, a course Shepard could firmly refuse, and later offering to examine volunteer geth to confirm their allegiance. Should she survive the conflict on Rannoch, she was sent to aid in the development and construction of the Crucible, dissatisfied with the device yet lending it her formidable skill. (Mass Effect 3)