For every kill she has a tattoo, and she is covered in ink. Subject Zero has been around; ran with gangs, joined a cult, and kept the haircut. A powerful biotic with a mysterious past, not much is known about Subject Zero other than she is drawn to brutality and violence. Her emotional instability doesn't help the fact that she can lift and discard enemies like trash with her biotic powers. She's dangerous, unstable, and extremely violent, exactly what Commander Shepard needs for his suicide mission.
To recruit Jack into your squad, you'll have to travel to prison ship Purgatory. She's been incarcerated for quite some time, but the Illusive Man has arranged for her release into your custody. Things don't go quite as planned, but you'll still end up with Jack on your ship when you manage to escape from the prison.
Pull, Shockwave, Subject Zero, Warp Ammo (Loyalty)
Heavy Pistols, Shotguns