She is a character introduced in Toaru Majutsu no Index. She is an operative of Annihilatus of the Russian Orthodox Church, which specializes in the hunting down of spirits that are not supposed to exist. Her form makes it's appearance early in the series during the Angel Fall Arc, however, her first actual appearance is seen much later in the series. She is hinted to be an avid drinker and doesn't mind enjoying Brandy in work hours even though she is not supposed to.
Sasha can easily be distinguished by her signature look, a red hood and cape (which hides her long curly blond hair) and matching pointy red shoes. Her torso and limbs are covered with leather belts, and has metal braces on her ankles, wrist and waist, the latter being used to carry her many eccentric weaponry. Under is small layer of clothing that covers her torso and her arms up to the wrist, and acts like a thigh-high socks, they are form-fitting which naturally shows Sasha's figure.
Sasha's skimpy dress can be attributed to her female superior –Vassilisa –who forced Sasha to wear it as part of her hobby.