Vivienne always had a serious streak, as shown in her warnings to William about the problems with trying to be an anti-hero. Of late, she has become serious more of the time due to the dire nature of the situation and her greater responsibility. Despite this, she also has a sense of humor and a certain degree of appreciation for the ridiculousness of the world.
Father: Her only living relative she cares about he doted on her providing her with a personal tutor, as well as trying his best to describe her despite the pressure put on him by the empire. He is also identified as the threat needed to put the thief in her place, thus identified as her largest weakness.
Mother: Despite dying at a young age Dartwick identified her as formidable with both bow and horseback riding. She was the reason that Dartwick took on her mission to steal from the empire as "payment" for her family's troubles. This eventually led her to develop into the Name of Thief.
William of Greenbury: During his tenure as leader of the band, Vivienne deferred to his most of the time but warned him that if he acted like too much of an anti-hero he would weaken his story and get himself killed.
Assassin: They appeared at one point to threaten her, proving that they can sneak up even on her.
She admits to not being particularly good looking compared to other nobles but she still is able to seduce others through the use of her charms.
Vivienne is a proficient burgler and pickpocket, usually able to move undetected and take things without even needing to use her Name. She is also fast and difficult to hit, though she lacks offensive power compared to most members of both her former heroic band and the Woe.
Her first Aspect, Hold, allows her to stow away objects in a pocket dimension. She can store even large, magical or dangerous objects in this way and prevent them from harming her or her allies while they are stored. This is shown when she used this aspect to store the Sun of Arcadia with no ill effects even though it burned her severely when outside of her pocket dimension.
Her second Aspect, Hide, allows her to move undetected past the scrutiny of most people and even past some magical alarms. Anything offensive or attention-getting on her part can break the effect, however, so she cannot use to to evade her enemies in combat.
Her third Aspect, Steal, is much more dramatic, it allows her to forcibly take objects from her opponents with a touch. Such as the Duke of Green Orchard's protective shield or the Sun of Arcadia, though she is not immune to being harmed by such things while doing or after so. This is evidenced by the way that she suffered severe burns on her hand when she used this to steal the Sun of Arcadia.
In addition to named powers, she is also a skilled spymistress. While her methods have not been described, she has been shown to be able to find a great deal of information, locate traitors among the nobility quickly, and to have a large number of people firmly under her control either by loyalty or intimidation.