Before her powers manifested, Cessily Kincaid was a popular high-school cheerleader in an Irish-American family. When her powers manifested at age sixteen, her body began to transmute from tissue to metal and she turned into a polymorphic puddle on the floor. She and her parents were horrified at her mutant "condition" which seemingly left her body inorganic. However, her powers went deeper than that, and had actually changed her entire physiology into a malleable metal substance. Embarrassed by this, they kept her inside and out of public view before sending her to the Xavier Institute for Higher Learning. Her parents never accepted Mercury after the activation of her X-Gene and were deeply ashamed of her.
Mercury first appeared in New Mutants Vol.2 #2 (August 2003). She was created by Nunzio DeFilippis, Christina Weir and Keron Grant.
Mercury was first introduced as a strong member of the Hellions Squad. She showed a great deal of loyalty to her teammates and fellow mutants. During 198, Mercury was one of the few mutants who maintained her powers and was placed into the New X-Men squad created by Emma Frost. Later on she had developed close friendships with the younger mutants and is now living on Utopia under the care of the X-Men.
Major Story Arcs
At the Institute, Cessily became part of the new Hellions Squad, mentored by Emma Frost. Ms Frost gave her squad the chance to chose their own code-names, and so Cessily named herself Mercury. In the Hellions, Mercury worked hard and made new friends. She developed a close sibling-like relationship with her squad leader Hellion. Her mutation seemingly inorganic made her immune to the 'death touch' of Wither. She quickly developed a crush on Wither, and confided in Hellion how she felt.
At a time when Wither wanted to leave the New Mutants Squad, Hellion made an open invitation for Wither to join them. However, Wither enjoyed his new friends in the Hellions Squad, and he remained infatuated with Wallflower, so Mercury's feelings were unrequited. Although she didn't push herself onto Wither, Mercury remained close to him and accompanied him to the school dance. Unfortunately, despite her efforts he confessed to Hellion that he still had feelings for Wallflower during the dance.
During the summer break, the Hellions made an eventful journey to Hellion's home in California. They had already run into trouble with airport security because they didn't trust either Rockslide or Mercury, due to their noticeably mutated physiology. The situation was diffused when Hellion made a call to his family's lawyers, but this only served to enrage his parents. Therefore, the Hellions received a cold and bitter reception from Hellion's parents. This spurred them to search the house for any secrets with which to blackmail them. Instead they found a spell to call the Kingmaker.
They collected the various herbs and performed the spell, which involved making a telephone call. When the call was answered, they were asked for their names. After that, the ceremony seemed to end with an anti-climax. However, the next day the Kingmaker arrived at the house and offered to grant any of their wishes.
Mercury's one wish was to be reunited with her parents who would love her. Sure enough, when she arrived home, her mother offered to take her out shopping, and her father introduced her to their neighbors. It was a dream come true for Mercury, and she enjoyed every moment with her loving parents.
However, she was so happy that they had accepted her that Mercury hadn't considered what had happened to make her parents change their minds. The Kingmaker asked the Hellions to help him secure a biological weapon. Yet when they discovered that they had been tricked into stealing the weapon, they broke their deal with the King Maker. Unfortunately the ramifications of severing their deal meant that Mercury's parents became aware of what had been done to them. They had been hypnotized by low-level telepaths, and when the process had been reversed, it made her parents fear and distrust Mercury even more.
The students at the institute were devastated by the effects of M-Day. Many who were desperate to keep their mutant abilities found themselves without their powers. Meanwhile, both Wither and Mercury were disappointed to discover that they had kept their powers. She longed to be a normal girl and go home to parents who loved her.
Since the student population had been radically decreased, the various Squads were disbanded. As a remaining student, she was forced to go into the Danger Room and enter into a Battle Royale with all the other trainees. The outcome of the fight resulted in a team of elite students who were branded the New X-Men. Mercury joined the majority of others from the Hellions & New Mutants in the new team of New X-Men.
However, almost immediately, their celebrations were cut short. The de-powered students had been sent home in waves. Many had already left the school, while others were getting ready to leave. Just as the New X-Men were watching a school bus of their friends leave the Institute, the bus was hit by a missile. Instantly, they saw their friends die in a ball of fiery metal. Mercury's reflective skin dazzled with the light from the flames, and she made desperate efforts to save her friends. Unfortunately, over 40 of their friends died, including the former Hellion, Tag.
After the Purifiers lost control of Nimrod, it attacked Forge and forced him to build it a new body. The New X-Men discovered what Nimrod was planning, and tried to alert the X-Men. However, Cyclops did not listen to them and dismissed them as children. Frustrated, the New X-Men decided to take action themselves, by stealing the plane and flying out to Dallas.
Mercury was among the New X-Men who went to Texas. They attacked Nimrod directly after it had assimilated a new body created by Forge. During the assault, it caught Mercury's hands and X-23 was forced to use her Adamantium claws to slice them off. Initially frightened and shocked from being amputated in battle, Mercury's powers allowed her to reform and grow a new pair of hands afterwards. She then played an important role in defeating Nimrod, as she used her limbs to hold open a cavity in Nimrod's chest. The cavity exposed the Nimrod's time device and allowed Surge to overload it.
Battered and weary, the New X-Men returned to New York. However, Emma Frost had already begun making attempts to evict X-23 from the Institute. Mercury had at first pitied X-23 for being a social outcast who didn't know how to express her feelings towards Hellion. As such, Mercury made efforts to befriend X-23 and reassure her that she had a home at the Institute. Soon after their return from Dallas, Mercury observed one of Emma Frost's attempts to remove X-23, and defended her new friend by verbally attacking her old mentor.
Together, Laura and Cessily went into town for coffee. Although there was a curfew placed on the student body, they still managed to sneak passed the Sentinel guards who were monitoring the 198. In town, away from prying eyes, they discussed X-23's obvious romantic feelings for Hellion. For Mercury, it was a chance to feel like a normal girl again, just as she had done when she was a cheerleader. She even made light-hearted jokes about having her hands cut off in battle, telling X-23 that she was trying to lose a few pounds.
X-23's training alerted her to danger, but Mercury seemed oblivious. Aware that they were about to be attacked, X-23 defended her new friend. Unfortunately, the cafe detonated as it came under attack from Facility agents. The girls were caught in the ensuing chaos, and X-23 cried for them to let her new friend go free. X-23 did not expect to see her former handler Kimura, who laughed at them and informed them that she wasn't there to collect X-23. They had been hired to kidnap Mercury.
X-23 was powerless to defend herself or Mercury against Kimura. Defeated and desperate she returned to the Institute to collect herself and any resources she could get her hands on. Her behavior started rumors, and when Hellion heard what was happening, he insisted on joining X-23 as she searched for Mercury.
At the Facility, Mercury was held in a test-tube like cell that prevented her from escaping in a fluid-metal state. There, she was subjected to all kinds of torturous experiments that made her scream out and faint from the pain. When awake, she begged for her tormentors to let her go home. Instead, she was informed that they need her skin for the creatures that Weapon X had biological engineered. The creatures were created to order; designed to hunt down and kill mutants, on behalf of The Purifiers. While imprisoned, samples of Mercury's skin were successfully extracted and grafted onto three of the creatures. The collection of Predator X finally had a metallic skin that would be morphic and help heal any wound. It was likely that the process would have continued if it were not for the surprise attack by X-23 and Hellion. Freed by her team-mates, Mercury then absorbed back her skin from two of the creatures, but one still managed to escape.
Upon their arrival back at the mansion, Mercury passionately hugged X-23. She emotionally lamented over how terrible X-23's childhood must have been for her to have grown into such a ferocious fighter.
Quest For Magik
Despite how she is usually determined, passionate and light-hearted, Mercury was traumatized by her experiences at The Facility. To make matters worse, she was then sucked into Limbo by Belasco. Mercury and Dust did their best to fight off the demon lord and sorcerer Belasco as he tortured and killed their friends searching for Illyana Rasputin. Fortunately for her, Mercury's powers granted her immunity to magic. Together, the New X-Men defeated Belasco and Illyana sent them all back.
During some much needed downtime at their home, Mercury went around the school questioning the students on how old they were in an attempt to find the youngest student. Unfortunately, the downtime didn't last long.
During Messiah CompleX, she accompanied the New X-Men in their assault on the Purifier's base of operations: a church. After their assault, she battled the final Predator X when it attempted to attack the students at the school. This fight ultimately led to her and the others participating in the final battle on Muir Island.
Some time later, Cyclops selected Mercury for a mission to Limbo because she had experience there when fighting Belasco. More importantly, she was selected for the mission because she had previously proven to be resistant to magic. She went along with Wolverine, Colossus, Nightcrawler, Rockslide, and Pixie. The mission was to save Illyana Rasputin and repair Pixie's damaged soul. However, Pixie's soul was nearly lost. The gathered group of X-Men barely survived, but made it safely back to San Francisco.
Mercury, along with fellow students Onyxx and Loa was tasked with keeping peace at the riots on Telegraph Hill after the mutant-hate group "Humanity Now!" marched from Sacramento to San Francisco to promote " Proposition X", displeasing many citizens of San Francisco, mutant and non-mutant alike. After the riots subsided on Telegraph Hill, Cyclops came and picked them up, taking them to City Hall. During the final battle against Norman Osborn's forces, along with Iceman and many of the other X-students, she takes on Mimic.
After Osborn's defeat to the X-Men and the official creation of Utopia, Mercury was involved in a media tug of war between Norman Osborn, her father and their claims that she was being held captive against her will. Although she confronted her father over the phone during a live television broadcast, and disputed his claims, going as far as calling him a bad father, her situation became more complicated as Deadpool intervened. Believing that he was doing them a favor, he attempted to kill Mr. Kincaid on live television, only to be stopped by Domino. However Deadpool is still attempting to follow through and kill Mercury's father. In the mean time the X-Men plan on having Mercury declared an emancipated minor in order to counter Osborn.
Like all the X-Men, Mercury was trapped on Utopia. During the build up to Bastion's grand plan, she was seen as a bystander in the mess hall during Hope Summers' and Dani Moonstar's fight.
Like all healthy and able-bodied X-Men, Mercury was sent to fight the hoards of Nimrods as they come flooding into San Francisco from a post-apocalyptic future. The first wave of Nimrod caught the mutants by surprise. Although Mercury wasn't hurt, she comforted Surge, who was left distraught after the first battle on the Golden Gate Bridge.
At first, Mercury patiently waited alongside Loa and Gentle. They remained in the medical bay, watching over Hellion's unconscious body. While watching over her friend, she was surprised to see Trance return to her physical body. Trance was alarmed as she had come under attack while in Limbo on yet another mission to rescue Magik. However, Mercury had to break the terrible news that they couldn't help as they were under attack from the Nimrods.
Powers & Abilities
Mercury has a unique physiology and exists as an inorganic, non-toxic metallic substance (not actually mercury). She is a metallic polymorph, able to shift into different shapes, both solid and liquid. In combat she can use this ability to reshape her limbs into sharp and melee weapons. It has been stated that Mercury subconsciously keeps her hair its original reddish color; this seems to indicate that she can change color in addition to shape. At the moment, it is as much of her original appearance that she has retained. Mercury is also able her to cling to surfaces (such as walls and ceilings), which in conjunction with her shape-changing grants her phenomenal stealthiness. However, the greatest consequence of her powers is that she is unable to revert back into her regular human form and therefore remains permanently in a metallic state.
Additionally, she no longer requires to food, water, or oxygen to survive; suggesting she may possess immortality. Although she does not need to eat, she does so anyway since it helps her feel more human. While she was held captive, it was revealed that her metal-based body can bond with carbon-based life (in a manner similar to symbiotes). It was in this manner that the Weapon X scientists bonded her metal to the tissues of their mutant devouring beasts, Predators X. She was also able to "feel" the presence of the Predators X once they were bonded to her.
As her body is made of metal, she is very hard to injure or damage with physical attacks. When Mercury's body is attacked in a physical assault, she can simply reassemble herself. The most notable injury she has sustained was when X-23 was forced to sever Mercury's hands with her adamantium claws and Mercury simply reattached her hands. It has been shown that she has a degree of resistance to magical attacks. She has immunity to biological assaults as she is no longer organic; Mercury is immune to Wallflower's pheromone powers and Wither's decay touch. As Wither's power effects all organic material, this therefore suggests that her body is completely non-organic (at the very least confirming that she is not a carbon-based lifeform). Being metallic, Mercury's main weakness is electricity. Large bursts of electric current can incapacitate her. Similarly extreme amounts of heat can also damage her, as seen when a high-powered laser burned and removed pieces of her skin.
Earth-58163: House Of M
In the House of M reality, Mercury was a member of New Mutants. Though the series featured an ensemble cast, Mercury was very close to Wallflower (even though she was an undercover espionage agent).
When Mercury discovered Wallflower's deception, she was incredibly hurt, while Wallflower tried to kill her.
In Other Media
Wolverine And The X Men
In Wolverine And The X-Men, Mercury was one of Magneto's Acolytes. She worked as a Genoshan peacekeeper, yet shared in Magneto's secret plans for the up-coming war between humans and mutants. She first appeared as one of the Acolytes, fighting a violent mutant who rampaged through Genosha.
She aided in the mutant's capture, but was later seen helping to calm him down. Later she was briefly seen breaking into the MRD's mutant detainment centre with the aid of the other Acolytes in order to liberate powerful and destructive captive mutants.