Rahna is an unseen character whom Kaidan Alenko refers to in discussions with Commander Shepard. According to Kaidan, she was one of the biotic potentials sent to BAaT when the Alliance and Conatix Industries first set the training programme up. She was Turkish and came from a rich family. Rahna had a close circle of friends on Jump Zero including Kaidan, who describes her as being smart, charming and gentle: everybody loved her and protected her.
Rahna was terrified of her instructor, Commander Vyrnnus, and with good reason. When Rahna became exhausted under his brutal regime and tried to pick up a glass of water with her hand instead of using her biotics, Vyrnnus punished her by breaking her arm. Kaidan retaliated, lost control, and ended up killing Vyrnnus with a "full on biotic kick". Though Rahna had been scared of Vyrnnus, now Kaidan scared her even more and things never worked out between them afterwards. It isn't known what happened to Rahna after BAaT was shut down.