Daina Le Guin is the tertiary antagonist in Dead Space 2, and a Unitologist member on Titan Station, apparently aware of the Second Aegis VII incident.
Outbreak on the Sprawl
Prior to the Necromorph outbreak on the Sprawl, the Unitologists on Titan Station planned to release Isaac Clarke from his EarthGov enforced stay in the asylum, Daina spearheading this effort.
Daina and Tyler Radikov are among the Unitologists who participate in the sabotage of the Government Sector and the provision of false information to recent Unitologist inductee, Karrie Norton (codenamed "Vandal"). The crossover tubes open and Necromorphs set loose on the station, Daina contacts Norton, thanking her for the spread of the infection, believing her death at their hands will be "glorious".
Shortly after the station is overrun, Daina and Unitologists set their plans in motion. Franco Delille frees Isaac and he tries to warn him of his current predicament only to be killed by an Infector. Daina, monitoring Franco's progress, urges Isaac to run before the Necromorphs in his area can kill him. Contacting him directly, Daina offers her assistance in Isaac's escape, promising to cure him of his dementia.
His initial behavior uncooperative, Isaac spurns her help and Daina leaves him on his own until he contacts her, reluctantly admitting she is his best chance to escape the station alive. Daina explains to Isaac what happened the three years he's been on the Sprawl. He is a target of Hans Tiedemann, who presumably wants him dead for his connections to incident on the Ishimura and Aegis VII.
Daina leads Isaac from the Titan Memorial Medical Center to Cassini Towers, wherein he begins to suspect her intentions as he travels deeper and deeper into the Titan Station Church of Unitology. Isaac hesitates, believing the church a dangerous location. Daina, unhappy with his continued behavior, reminds him that she lost a brother saving him and knows her plan will work. She directs him to a safe room in the complex and waits for his arrival. Daina reveals nothing of her intentions until Isaac reaches the rendezvous point and two of her men apprehend him.
Within her grasp, Daina reveals the "cure" for Isaac's dementia was a ruse to lure him to her. Unlike Tiedemann and the Earth Government, who want the likes of Isaac and Nolan Stross dead, Daina and the Unitologists need him alive to maintain the "blueprint" the Red Marker imprinted on his mind in order for the church to create their own Markers.
After revealing her plans to Isaac, an EarthGov Gunship destroys the shuttle docked outside and proceeds to penetrate the room's containment glass. The gunfire from the ship dismembers and kills Daina and her accomplices, allowing Isaac the chance to escape from both groups.