Jack

"Turns out, mess with someone's head enough and you can turn a scared kid into an all powerful bitch."

Jack, also known as Subject Zero, is a human biotic who appears in Mass Effect 2.

Jack is voiced by Courtenay Taylor.

Subject Zero
Subject Zero is her class power. It may be evolved to Primal Adept and Primal Vanguard.

Dossier
A young woman with a mysterious and violent past, she was once the subject of experiments that resulted in an enhancement of her biotic abilities; which had the added side effect of her unpredictable and fiery personality. This manifests itself in a lust for combat, a tendency to spout profanities and a body covered from head to toe in elaborate tattoos, marking kills and events in her life. She has killed various gangs, run with various gangs, was a pirate for a while, crashed a space station into one of Kajhe's moons, and at one point was a cult member, keeping her head shaved after her departure. She is described by Shepard as "dangerous, powerful and extremely violent." She is a potential romance interest for a male Shepard where it ends in two ways; a Paragon ending for the Relationship or a Renegade ending.

After gaining the loyalty of both Miranda and Jack, the next time Shepherd boards the Normandy Joker will radio in about a fight aboard the ship. Jack wants Miranda to admit what was done to her by Cerberus was wrong, but Miranda refuses to acknowledge that Cerberus was at fault claiming it was a splinter group not Cerberus calling the shots. Choosing one will lose you the loyalty of the other and the chance for romance with them, though they still keep their alternate outfit and additional skills. Alternativly, you can choose neutral options, and keep the loyalty of both.

Subject Zero's Appearance
Jack's extensive tattoos suited her personality better than clothing or armor. The final designs were intricately crafted as a visual story of her past, according to the Art Book included with the Collector's Edition.

Trivia

 * If you bring Grunt with you to Purgatory to collect Jack, he'll have a particular interest in her after she is released and begins to escape. Grunt says such quotes as "Oh I want to see this!" and "Move! I want to see how long she'll last," when pursuing her.
 * She periodically yells "I will destroy you!" when in combat and/or using abilities, akin to most humanoid enemies in first Mass Effect.
 * The Name "Jack" may be a possible refrence to a character with the same name, and personality, in the 'Riddick' Series.