Mary

Mary (メアリー Mearī) is a member of the Avatar cult.

Appearance
Mary is a petite young woman. Her pink hair is cropped short, reaching only up to her shoulders and elegantly framing her dainty face. A thick bang hangs down her temple and between her eyes. The most striking feature about her face is her large eyes. The irises are golden and appear to have diamond-shaped symbols engraved into them in place of pupils.

Mary wears a simple dress with a turtleneck. The upper part and the sleeves are black. The sleeves are much longer than her arm and, hence, rolled back into cuffs, revealing the underside to be white. The lower part of the dress is white in color, the two colors clashing at the chest in a jagged pattern. The dress reaches up to her thighs, and the bottom edge of the dress is also black, flaring out like a mini-skirt or frock. A necklace with crescent-shaped links adorns her neck, the pendant laying on her chest. The pendant is a simple light blue stone with a golden frame. She also wears a simple black headband that gives her the appearance of having feline ears.

Personality
Like all other Avatar members, Mary appears to be an ardent follower of Zeref. Aside from this, she is quite childish, calling out others on any lame puns that they make. She is also carefree, treating a serious matter such as a spy in their organization lightheartedly. She has a quick temper, causing her to make bad decisions such as attempting to engage Lucy in a melee when the latter is using the Taurus form of her Star Dress. But this quick temper is accompanied by an extremely small attention span as she can go from furious to mischievous in a moment.

Despite her childish traits, her personality is extremely twisted. Her sense of humor is quite morbid and pessimistic, causing Briar to call her "Poison Tongue", much to her fury. She also finds dark things like Gray's thirst for revenge quite cool, further proof of her somewhat skewed mentality. She has exhibited sadistic tendencies, using her Magic to torture Lucy even after she had been rendered helpless.

Avatar arc
At a meeting of Avatar cultists, Mary vows to purify the world for the sake of Zeref, then grins at Gray, another participant of the gathering. Later, when Jerome reports that Arlock refuses to give an immediate decision on how to deal with any interference caused by the Magic Council, Mary jokingly suggests that somebody might actually come for them due to the old man's stubborn attitude and gets angry when Briar scolds her for the macabre joke, stating that Briar's habit of coming up with terrible nicknames for others is worse. Her fury is short-lived as she immediately teases Goumon's word play. When the topic about there being a spy amongst their ranks is brought up, she seems to agree with most that Gray is the likeliest candidate as he is a former Mage of Fairy Tail. When Gray reveals his objective for joining Avatar and his pure lust for revenge against E.N.D., Mary remarks that nobody as dark and evil as Gray could work alongside the Council, also saying that he is quite dreamy.

Later, she heads down to the basement and helps capture Natsu, Happy and Lucy, who have broken into their headquarters. She uses her Magic to gleefully torture Lucy and mocks the former Fairy Tail Mages, also admonishing Goumon and Abel for trying to take on opponents above their caliber. After the prisoners have been successfully imprisoned, Mary heads out with the rest of the cultists to attack Malba City. As Arlock rouses Avatar's members with a speech, she happily states that she will finally get an opportunity to meet Zeref. They soon begin their assault, but Mary is astounded to see their vanguard blown back by none other than their prisoners, who have been freed by the traitorous Gray. She is impressed by their opponents' monstrous power and decides to help out in the battle against them.

She soon approaches Lucy and uses her Magic to halt her and Taurus' rampage by creating a virus in their intestines. As the two collapse from the pain, she mocks them and says that her Magic could be lethal if she created a virus in their brain. But she never gets a chance to show her prowess as Wendy arrives at that moment and nullifies the virus using her healing powers. Enraged, Mary attempts to physically assault Lucy, but receives a punch enhanced by her Taurus Star Dress instead and collapses. Prone on the ground, she gloats when Arlock summons Ikusa-Tsunagi, but her joy is short-lived as the old man reveals that he plans to sacrifice all the Avatar members to summon Zeref. When Natsu defeats the God with one blow, finally ending Avatar's plans, she tearfully wonders what kind of people their opponents are to have defeated an entire army and a God on their own. She, along with most other cultists, is then arrested by the Rune Knight squad led by Gajeel.

Magic and Abilities
Virus (ウイルス Uirusu): Mary uses an extremely sinister form of Black Magic that allows her to create a virus anywhere in her opponent's body. She claims that the virus eats at the victim from the inside. She is proficient enough to easily cause intense pain in multiple individuals including powerful Mages such as Lucy Heartfilia. Although she is capable of using it to cause brain death, she seems to prefer to watch her victims squirm as she targets their intestines.

Quotes

 * (To herself) "All in the name of Zeref."
 * (To Lucy Heartfilia) "Does it hurt? It hurts, doesn't it? My Black Magic."
 * (To herself) "I'll finally be able to see Zeref."
 * (To Lucy Heartfilia) "Your life is at the mercy of my Virus. For example, let's see ... if I decided to, I don't know, target your brain ..."