Her original name, Mary, was given to her by her father Arkham, but she chose to renounce that name when he murdered her mother. Dante first called her "lady" when she refused to tell him her name. She has differently-colored eyes. While still a normal human, she is also an exceptionally skilled firearms expert and extremely acrobatic in close quarters combat. Her most powerful weapon is the Kalina-Ann, a customized missile launcher similar to a MANPADS.

In the anime, voiced by Fumiko Orikasa, she works as a solo devil hunter but sometimes calls on Dante for jobs, and sometimes money that he owes her.