She is voiced by Eri Suzuki in the Japanese version and Dani Chambers in the English version of the anime. The latter also voiced Dahlia Hawthorne of the Ace Attorney anime.
Like other members, she appears in the meeting. Unlike Jerome and Briar, she doesn't suspect Gray Fullbuster, a new member of the cult, being a threat and even make jokes when Goumon says they could be suspected for their evil plan. When Natsu Dragneel and Lucy Heartfilia break in Avatar's base, she stops Lucy from talking Gray down with her Virus magic to incapacitate and torture Lucy short before Avatar imprisons them. She later appears with some other members at "Operation Purification". When Jerome takes on Erza, Mary once again targets Lucy and tortures her along with Taurus and Happy until Wendy and Carla arrive and negate her Virus magic. She then tries to sneak attack Lucy, but Lucy manages to turn with Wendy Marvel's help and Lucy defeats her with a single blow. Later she's arrested by Gajeel Redfox 's Custody Enforcement Unit.
Mary is a young pink-haired woman with orange eyes with golden star pupils, who wears a black and white dress and black shoes. She also seems to wear a pendant around her neck.
Like other members, she is a Zeref fanatic. She is also sadistic, gleefully laughing when she tortures her foes and carefree who doesn't take being suspected to planning to slaughter a town seriously.
Power and Abilities
Virus (ウイルス Uirusu): She uses a sinister and a very dangerous form of Black Magic (黒魔術 Kuro Majutsu), which attacks, with the pure power of thought, the opponent's body and can kill them by attacking their head or hearts. She likes to use it to torture her foes.