Dahlia is, in fact, a slaver and the leader of a band of pirates in the Artemis Tau cluster. Her group specializes in slaving, and includes humans, turians, and krogan, operating out of a stronghold on Sharjila. Dahlia, though not an asari commando, is a formidable biotic and a well-trained combatant.
Dahlia is actually the black sheep of a prominent family; her sister, Nassana Dantius, is a diplomatic emissary on the Citadel. Knowing Nassana would be heavily monitored or even demoted if her sister's activities are revealed, Dahlia decides to blackmail Nassana and receives a large sum of credits as a result.
Unfortunately, Dahlia underestimated her sister. Nassana retaliates by contacting Commander Shepard. She claims Dahlia is an innocent victim who has been kidnapped by mercenaries, and points the Commander to Dahlia's base. Taken by surprise, Dahlia rallies her men to defend the base, but is killed in the assault.
Dahlia is armed with a pistol and an assault rifle, and is a biotic. She mostly or always comes down from the upper level, strafes to her left and hugs the wall (while moving toward the back of the room), until she reaches roughly the halfway point of that wall; at this point, she heads for Shepard. In this maneuver, she tends to be accompanied by a (human) sniper. Using this tactic, most of her pirates will have already begun attacking Shepard and squad, and accordingly her biotics become an unwelcome surprise to the fight. As with most fights in such an environment as her compound, however, crowd-control powers provide a large advantage. Use throw, singularity, lift, or the like, to knock her and any nearby enemies off their feet, making them easier targets for your weapons.
- Being that her identity was unknown at the time she was killed, she is labeled as "Asari Slaver" in the course of the fight as opposed to her actual name.