She was originally involved in a plot created by Sebastian Shaw to have his revenge against Sage and gain control of the Sydney underworld. In an attempt to make Sage work for Shaw again, Lady Mastermind placed her in a series of illusions. However, with the assistance of Lifeguard, Sage was able to break the illusion and reflect Regan's powers back against her, leaving her in a vegetative state.
Joining The X-Men
Regan is one of few mutants that retained their superhuman powers after M-Day. Cannonball and Iceman find a comatose Regan, along with a partially disassembled Karima Shapandar. It was stated that Regan fell victim to scientists of the Fordyce Clinic who were trying to determine if a person can catch mutation like a disease. Regan finally awakened from her coma after her powers had been temporarily hijacked by Serafina. She joins Rogue's strike force/field team, but Rogue told Regan that she is only wearing the X-Men uniform because she was found with nothing more than a white sheet. Soon afterwards, the team was ambushed by Pandemic's forces, which captured Rogue and teleported to an unknown location. Eventually, Karima Shapandar was able to restart the teleportation device, but things did not go exactly as planned. Regan was teleported up high into the air and fell from an enormous height. Luckily, Iceman managed to catch her before she hit the ground. Mystique, who was also teleported by the machine, was not as lucky as she was, and vanished. Regan and Iceman soon regrouped with Karima Shapandar, and the trio began to search for Pandemic. They find Pandemic and defeat him but Rogue is infected with Strain 88 in the process. The team goes to Cable's island utopia of Providence to find a cure for Rogue. While there the island is attacked by an ancient Shi'ar superweapon known as the Hecatomb, forcing Regan and the rest of the team to fight the psionic horror. The weapon is eventually defeated thanks to Rogue's power-absorption abilities, now supercharged due to Strain 88.
When Rogue's team of X-Men goes to one of Mystique's safe-houses an intruder alarm later goes off. Initially confused by the seemingly invisible nature of their opponents, the X-Men are caught off guard when Regan drops her illusionary cloak to reveal the Marauders. Regan later fights alongside the other Marauders in Flint, Michigan, against Iceman and Cannonball, as both sides try to obtain the Diaries of Destiny.
Along with fellow Marauders Sunfire, Gambit, Prism, Blockbuster, Malice, and Scalphunter, Regan travels to Cooperstown, Alaska to find the baby but instead come across the Purifiers and they come to blows. The next time Regan is seen is when the X-Men send a strike force to confront the Marauders. Working with Malice, she disguises an unconscious Scrambler as Angel and Malice drops him on Wolverine canceling out his healing factor. Malice says this illusion is courtesy of Regan and boasts how she is a retired X-Man. Nightcrawler teleports in and kicks her in the head knocking her out. When the X-Men, X-Factor, and X-Force arrive on Muir Island, Lady Mastermind attempts to cast an illusion to hide the Marauders. However, Wolverine picks up her scent and stabs her in the abdomen.
Sisterhood of Mutants
The Sisterhood approaches Regan, who is at a graveyard mourning her father. At first, Regan points her gun to Madelyne Pryor's head. When Madelyne promises to resurrect Regan's father, Regan joins - this, however, disgusts Martinique. Later in San Francisco, the Sisterhood perform a spell involving Kwannon's body and a captive Psylocke, restoring her to her original body. Later, when the Sisterhood attack the X-Men, Regan takes out Emma Frost by trapping her in an illusion and then leaving her bound and gagged in a dark room, cutting her off from her senses. While trapped, Emma unexpectedly finds what seems to be Jean Grey communicating to her, and seemingly aiding Emma. Emma becomes the first person not to fall for Regan's illusion, prompting Regan to worry. Emma then savagely beats Regan, calling her a traitor to her kind. Emma leaves Regan's bruised and battered body upon the ground, though the Sisterhood later pick her up and escape. When they return to base, the Red Queen orders Regan, Martinique, and Psylocke to stay while she and the other members of the Sisterhood go to Jean Grey's grave. They take on Storm, Dazzler, Karma, and Emma Frost who savagely beats her again. After the Red Queen's defeat, Spiral collects the Sisterhood and teleports off.
Powers and Abilities
Telepathic Illusions: Lady Mastermind possess the mutant power to project extremely convincing and realistic illusions into the minds of others, a stronger variation of the same ability her father had.
Her illusions are hypnotic, and her victims tend to accept them as fact, even when the images and scenarios they are confronted with involve sudden changes to the world around them, or are inconsistent or improbable (for example, Rogue, when under Lady Mastermind's control did not question the sudden existence of a multitude of Vargases, or the random jumps in location and time she was experiencing). As such they can be used as a very effective brainwashing tool. In addition, unlike her father, both Regan and her half-sister Martinique have limited telepathic abilities that enable them to read their foes minds and make their illusions all the more accurate for it. Regan's illusions have also been shown to persist even after she has been rendered unconscious.
Psychosomatic Symptoms: Regan's powers can also kill, as her victims bodies respond as if her illusions are real. She confronted Viceroy with the illusion that he was drowning, and believing it to be real, he suffocated, despite having no physical injuries and being in a room with sufficient oxygen. Heather Cameron's body also responded in a similar way, bleeding through the pores in her back when she was under the illusion she had been stabbed.
A pair of handguns.
- Lady Mastermind (Regan Wyngarde) was initially intended to be the Mastermind II (Martinique Jason) that had appeared previous in such comics as Daredevil. However, both Chris Claremont and Peter Milligan intended to use the character at the same time so an editorial decision was made to differentiate the two.
- Lady Mastermind has a distinct personality, to a point where writer Mike Carey refers to her as an "exuberant, sexy sociopath". Regan's brief tenure as an X-Men has granted her the X-Men uniform, something she still wears proudly even after attacking several of the X-Men.