19th century Born in Milbury House in Victorian London,
Nathaniel Essex is the son of Admiral Erasmus Essex and Mary Essex. Earning a full scholarship to the
University of Oxford, Essex becomes a biologist in 1859 and marries his wife Rebecca. A contemporary of
Charles Darwin, Essex becomes highly interested in research regarding evolution and "survival of the fittest." He concludes humanity is undergoing increasing mutation due to what he calls "Essex Factors" in the human genome. After the loss of his four-year-old son Adam due to birth defects, Essex becomes more obsessed with his research in perfecting and improving the human race. Arguing that science is beyond morality, his questionable research methods and ideas lead to suspicion, mockery, and finally ousting from the Royal Society and the scientific community. Angry and bitter, Essex accepts that being a "monster" in the eyes of others may be necessary to achieve his goals. Essex hires the criminal gang known as the
Marauders to kidnap homeless people as test subjects for his experiments, including a man named Daniel Summers (an ancestor of
Scott Summers). Essex learns that some humans are born with
mutant genetics that make them superhuman and discovers that one called
En Sabah Nur (Apocalypse)) is in hibernation. The Marauders awaken En Sabah Nur who then offers Essex an alliance, believing they have similar goals in perfecting the world and humanity. Nur then intends to conquer 19th-century England but is confronted by
Cyclops and
Phoenix, heroes from the future who arrive via time travel. In 1899, Apocalypse emerges from hibernation again and is pleased with Sinister's work, including the development of a deadly
techno-organic virus. Sinister then injects the virus into Apocalypse, but it only weakens the villain. As Apocalypse returns to hibernation to heal, he promises to kill Sinister when next they meet. Sinister decides to engineer
a mutant who can kill Apocalypse.
20th century In 1907, Sinister works at the
Ravencroft Institute and employs the mutant killer and mercenary
Sabretooth as an agent. Sabretooth brings him the mutant called
Logan for experimentation, but the man is then freed by coworker Dr. Claudia Russell (ancestor of the werewolf
Jack Russell). Sinister leaves Ravencroft afterward. In 1912, Sinister encounters
Grigori Rasputin and encourages him to father many children, promising they will have superhuman potential. Rasputin's descendants later include siblings
Colossus,
Magik, and Mikhail Rasputin. A few years after meeting Rasputin, Sinister grants shape-shifting abilities to Jacob Shaw (father of the X-Men villain
Sebastian Shaw). It is possible that during the 1920s, Sinister also gave Herbert Wyndham information regarding how to map and break the human genetic code. Wyndam, a student of the
Inhuman scientist
Phaeder, later becomes the master geneticist called the
High Evolutionary. During World War II, Sinister works with the Nazi
Josef Mengele, experimenting on children. He also encounters a young
Max Eisenhardt (Magneto). Sinister leaves the Nazis, concluding they will lose the war. Sinister's research during World War II is later recovered and used by the
Weapon X project. Following World War II, Sinister adopts the name "Dr. Nathan Milbury" again and works on
Project: Black Womb with Dr. Kurt Marko (the father of
Juggernaut), Dr. Alexander Ryking, and the precognitive mutant
Irene Adler. They conduct research on many mutant children and take note of several families that may produce mutant children later, allowing Sinister to monitor these bloodlines for decades. Concerned his own physical death may be inevitable, Sinister uses the Cronus Device to implant his own hidden cells of his genetic information into the DNA strands of the Marko, Ryking, Shaw, and
Xavier family lines. In time, their descendants can act as hosts for Sinister's consciousness. During the Vietnam War, Sinister sets up a lab in Saigon and has his agent
Scalphunter bring him soldiers and civilians for experimentation. In 1968, Sabretooth investigates Sinister's operation but is then bribed and blackmailed to not interfere. Some years later, as "Dr. Milbury", Sinister becomes a professor at the University of Oxford. His students include
Moira MacTaggert and the mutant telepath
Charles Xavier, who realizes he cannot sense Milbury's thoughts. Years after Sinister's time at Oxford,
Dark Beast, a corrupt version of future X-Men member
Hank McCoy from an alternate timeline known as the "
Age of Apocalypse", enters the mainstream Marvel reality. This version of McCoy is a former student of his reality's Sinister. Dark Beast makes his way to New York City and experiments on many mutants, using techniques his Sinister taught him. Several of his surviving test subjects become deformed or disabled by their own abilities as a result, choosing to hide underground and join a sewer-dwelling mutant community known as the
Morlocks. Dark Beast's experiments indirectly lead to Sinister ordering the
Mutant Massacre.
Jean Grey and Scott Summers Returning to America, Sinister creates an orphanage to monitor some of the children of families he first observed during Project: Black Womb. The State Home for Foundlings in Omaha, Nebraska hides a high-tech, underground laboratory. Later, young Jean Grey's mutant telepathy prematurely activates when she witnesses the death of her best friend. Becoming aware of Jean's power, Sinister plans to kill her parents and bring her to the orphanage, only to learn the Greys have already contacted the now adult Charles Xavier for help, due to his background as a leading geneticist and psychological expert in trauma cases. Not wishing to be detected by Xavier, who at this point has already fought terrorists and superhuman menaces, Sinister decides to keep his distance after acquiring a DNA sample from Jean. As part of his long-term plan, Sinister allows Scott Summers to be adopted by a criminal named
Jack Winters, who abuses the boy and forces him to help with crimes. Rather than bend to his abusive guardian, Scott resists and is discovered by Professor Charles Xavier and his ally FBI agent
Fred Duncan. With Duncan's help, Scott becomes Xavier's ward and the first official recruit of the original
X-Men, a team of mutant heroes trained to stop mutant terrorists. Jean Grey joins this same team weeks later. Sinister continues to monitor Scott somewhat but keeps his distance so the telepathic Xavier and the other X-Men do not become aware of and interfere with his plans. Not long afterward, Sinister hires the villains
Blob and
Kraven the Hunter to fight and wound each of the X-Men. This results in a battle that draws the attention of the teenage hero
Spider-Man. Kraven then brings the blood samples of the X-Men and Spider-Man back to Sinister for study, even providing a sample of his own DNA. Sinister concludes that offspring of Jean Grey and Scott Summers could represent the ultimate stage of mutant potential, possibly a mutant capable of destroying Apocalypse. Using Jean Grey's cell sample, Sinister creates a clone who is rapidly aged. When the clone shows no sign of the X-gene, Sinister leaves her in a hibernation chamber. Years later, Jean Grey suffers catastrophic radiation poisoning but is saved by the cosmic
Phoenix Force, who desires her to be a host. With her increased power, Jean creates a new body for her consciousness and the cosmic Phoenix Force to occupy, while creating a healing cocoon to repair the damage done to her original body. As "Phoenix", Jean becomes a more powerful hero. She is later temporarily corrupted, causing the Phoenix Force itself to become a corrupt and deadly entity. The new "Dark Phoenix" asserts control, burying Jean's personality. Jean's personality later resumes control and she eventually kills herself rather than allow Dark Phoenix to rise again and destroy more lives. Without a host, the Phoenix Force reverts to its original nature and feels remorse for its role in Jean's death. To make amends, it restores Jean's consciousness to her original body, now fully healed. Simultaneously, the Phoenix Force causes a spark of life in the Jean Grey clone Sinister created. Before sending his Marauders against the Morlocks, Sinister learns the Avengers have discovered Jean Grey is alive and well in her cocoon. Sinister decides to seize the opportunity and at last kidnap Nathan Summers for experimentation. When Scott Summers learns of Jean's reappearance, Sinister mentally influences him to immediately leave Alaska to see for himself that it's actually her, leaving his family behind and without protection. Sinister then continues his mental influence, causing Scott to abandon his family and remain in New York City with Jean and the other original X-Men recruits. With Cyclops gone and occupied, Sinister sends his newly formed Marauders to attack the now vulnerable Summers house in Alaska. The Marauders attack Maddie and leave her for dead, then take Nathan Summers to the State Home for Foundlings. Meanwhile, Sinister erases all records of Maddie and arranges for the furniture from the house in Anchorage to be removed. Unbeknownst to Sinister, Maddie is taken to a hospital and survives, though she slips into a coma.
"Mutant Massacre" and "Inferno" Returning to New York, the Marauders are finally sent after the Morlocks. Using his stealth and tracking skills, Gambit leads the group to the Morlock community but abandons the group when he learns they intend murder. The Marauders dismiss Gambit and begin their slaughter, causing the "
Mutant Massacre" event, a series of battles that include the X-Men, the new X-Factor team, and other heroes such as
Thor. Some of the Marauders are killed in action. Scanning the mind of Sabretooth, the X-Man called
Psylocke learns the massacre was ordered by someone called "Sinister", alerting the X-Men to his presence for the first time. Soon afterward, Cyclops returns to Alaska to make amends with Maddie and be a father. Discovering the house is completely empty, he concludes Maddie left with Nathan, deliberately leaving no trace of where she might be. He is then confronted by
Master Mold, the robot whose primary task is to create mutant-hunting
Sentinels. During the battle, Master Mold refers to Cyclops as one of "the Twelve" who must be destroyed. Later on, Master Mold explains the Twelve are "The dozen mutant humans who will one day rise up and lead all of mutantkind in war against
Homo sapiens in the twilight of Earth." Months after Nathan's kidnapping, Maddie awakes from her coma, amnesiac. After regaining her memory, she contacts and reunites with the X-Men. Now bitter and increasingly desperate regarding her missing child, Maddie believes Scott completely abandoned them and never cared enough to contact her or look for her. She later joins forces with the demons
S'ym and
N'astirh who take advantage of her state of mind and corrupt her, turning her into the Goblyn Queen and leading into the "
Inferno" storyline. During this storyline, the mutant precog Irene Adler (now calling herself Destiny) sends the X-Factor team to Sinister's lab where they discover and rescue Nathan along with other children. The Goblyn Queen then arrives and retrieves Nathan and several other babies to use as sacrifices for a demonic ritual. Sinister reforms his Marauders, even resurrecting the fallen ones through his now perfected cloning technology. He then confronts Madelyne and reveals her true origins. At the end of Inferno, Maddie dies and her life-force and memories merge with Jean Grey's. As the X-Factor and X-Men teams fight Sinister, the villain reveals his many manipulations of Scott Summers over the years, how he mentally influenced Scott to abandon his family, and his quest to create offspring from his and Jean's DNA. and allies with
Stryfe, now leader of the terrorist Mutant Liberation Front. During this time, he establishes a new cover identity of "
Mike Milbury", a neighbor to Scott Summers' grandparents. During the storyline "
X-Cutioner's Song", Stryfe gives Sinister a canister he claims contains a sample of his own genetic material, in exchange for a service. When Sinister opens the container, he is angered to find it seemingly empty. He later realizes that he unknowingly unleashed the
Legacy Virus, a pathogen engineered by Stryfe that targets mutants. Not long afterward, Scott Summers meets Mike Milbury, who then reveals himself to be Sinister, still alive. Sinister warns of the Legacy Virus and also hints that there is a third Summers brother unknown to either Scott or Alex. When the villainous
Dark Riders arrive to attack Cyclops, Sinister declares the mutant hero under his own protection. Not long afterward, Scott and Jean Grey marry while Sinister monitors from afar, interested in the possible offspring that may result. Some time later, he recruits a new agent named
Threnody, a mutant who can sense the dying and draw energy from them. Not long after Scott and Jean's wedding, the X-Men learn that due to an alteration to history, their reality is about to be replaced by another. Believing they are about to die, the X-Man Rogue kisses her teammate Gambit, something she had not done before due to the risk that her energy absorbing abilities could harm him. During the kiss, she sees his memories and learns of his past relationship with Sinister. The alteration to the timeline is due to Xavier's powerful mutant son Legion traveling back in time to kill Magneto before the X-Men have even formed, but accidentally killing Charles Xavier instead. This creates a new "
Age of Apocalypse" reality where Apocalypse conquers much of the Western hemisphere and Magneto forms his own team of X-Men rebels, naming them in honor of his fallen friend Charles. In this reality, Sinister helps Apocalypse rule, adopts both Alex and Scott Summers as his personal soldiers, and recruits Henry McCoy (Dark Beast) as his lab assistant. Believing Apocalypse will ultimately destroy the Earth in his quest to eliminate the weak, Sinister still works to create a living weapon against him using DNA from Scott Summers and Jean Grey. The result is a powerful teenage mutant named
Nate Grey. Later on, the timeline is restored. Rogue is disturbed by Gambit's connection to Sinister, which is later revealed to the rest of the X-Men. This drives a wedge between them and Gambit for some time.
2000s Apocalypse gathers the Twelve, now revealed to be twelve powerful mutants he can use to ascend to a god-like state of power, with Nate Grey acting as a new host. After this plan fails, Sinister takes on the appearance of an elderly man, "Dr. Essex", and visits the
High Evolutionary. He influences the powerful geneticist to use his advanced space station to remove the powers of all mutants on Earth, causing widespread injury and several deaths, including most of the community of evolved mutants known as the Neo. Sinister then reveals his true nature and takes over the High Evolutionary's satellite, intending to use it to alter the genetics of people at his discretion, making Earth a giant lab where he could create the ultimate race of superhumans. Sinister's plan is then stopped by the X-Men, who restore mutant powers to all of those with the X-gene. The surviving Neo then hunt Sinister to avenge their fallen members, killing 17 clone doppelgangers. Sinister later resurfaces as
Dr. Robert Windsor, experimenting on mutants again, with Scalphunter acting as his bodyguard. Later on, an encounter with Colossus and the hero's brother
Mikhail Rasputin reveals that Sinister's powers are weakening and he is becoming desperate to find a way to restore them. During the storyline
Blinded by the Light, Sinister sends the Marauders and
Acolytes to murder all those who have knowledge of the future. Some time later, the first new mutant since M-Day is born. Sinister sends agents to kidnap the child in the storyline "
X-Men: Messiah Complex." Later, Sinister (whose powers are still weakened) is confronted by
Mystique, who presses the villain's face against an unconscious
Rogue. Rogue's energy absorption abilities are amplified at the time, causing her skin-to-skin contact with Sinister to kill the villain almost instantaneously.
2010s Mister Sinister is eventually able to fully possess the fifth clone of Alice, returning in
The Uncanny X-Men #544. Now dressed in Victorian-era garb and using knowledge gained from Apocalypse, he merges with the alien giant known as the
Dreaming Celestial, gaining great power. Sinister turns San Francisco's residents into doppelgangers of himself and attempts to create a society resembling 19th century England, which he claims to now see as a perfect culture. His true plan is to gain the attention of the alien Celestials so they might deem humanity too chaotic and then eradicate the species, leaving him to rebuild the planet with a better version of humanity. The X-Men restore San Francisco and defeat Sinister, who loses his enhanced power. Foreseeing the Phoenix Force will one day return to Earth, Sinister tells the young mutant Hope Summers about its existence, knowing she will be its choice for a new host. In truth, he intends to steal the Phoenix energy by using a group of
Madelyne Pryor clones. When the Phoenix Force arrives on Earth during the "
Avengers vs. X-Men" storyline, its power is divided between five people, including Cyclops. The Phoenix Five track down Mister Sinister, learning he has built his own city (based on Victorian-era London) within
Subterranea that is inhabited by clones of himself, several of his agents, and some acquaintances. Sinister orders his clones to war against the Phoenix Five. After help arrives, the Phoenix Five kill each and every clone of Sinister present. In the aftermath of "Avengers vs. X-Men," Sinister visits Cyclops and explains that some time ago he killed the X-Men public relations manager Katie Kildare, placing his own personality in the woman's mind while a secondary Sinister clone was left in charge of the city. While his clones and resources are gone, he still lives and will strike again. Sinister, now again in a cloned body of his old form, then infiltrates the X-Men's original mansion home, recently renamed the Jean Grey School, through its student
Ernst. Ernst provides Sinister access to DNA samples from the mutants within the school in exchange for providing her friend
Martha Johansson with a new body. His efforts are ultimately foiled by the students and Spider-Man, who was asked by Wolverine to help locate the school's mole. Sinister escapes but his new DNA samples are destroyed.
All New, All Different When the Inhuman city of
Attilan is under attack, its leader
Black Bolt releases
Terrigen Mist across Earth, the same mutagenic agent derived from Terrigen crystals that unlock an Inhuman's superhuman potential. This causes many humans with latent Inhuman genes (due to an ancestor) to discover new powers. It also proves deadly to mutants after sustained exposure. Mister Sinister experiments on unwilling subjects obtained by his Marauders to see if Inhuman and mutant DNA together can create a genetically superior species. His tests prove such a species would be unstable. After witnessing the explosive death of a test subject that is an Inhuman clone of Cyclops, Sinister is defeated by the X-Men. He and his Marauders were mentioned to have been arrested by
S.H.I.E.L.D. During the "
Hunt for Wolverine" storyline, Mister Sinister's cell samples of Logan are stolen by a thief who attempts to auction them off. Sinister attacks the thief but is then fought by X-23, who forces him to retreat. The auction attendees are evacuated to
South Korea's National Intelligence Service Helicarrier as
Iron Man,
Jessica Jones,
Luke Cage,
Spider-Man, and
X-23 interrogate the seller Declan Fay. He directs them to the
Kerguelen Islands where Mister Sinister has collected the genetic make-up of every person on Earth. Sinister reveals a kill team recently stole his work. The heroes then destroy his database before leaving. Soon after this, Sinister becomes highly interested in
Iceman's increased power and control.
The Quiet Council In the 2019
Powers of X series, it is revealed that at some point in the past, Sinister created his first clone community on an island in the South Pacific, calling it Bar Sinister. While here, he is approached by Professor Xavier and Magneto regarding his collection of DNA samples. Xavier asks Sinister to prioritize cataloging mutant DNA to create a comprehensive database that would be safe, secure, and redundant. In exchange, he offers to provide samples Sinister would have trouble getting on his own. The lead Mister Sinister clone is not interested in the deal, but is suddenly killed by another Sinister clone who has a functional X-gene, making him a mutant too. This Sinister clone becomes leader of the community and agrees to have his memories of this deal and encounter telepathically repressed until the day Xavier and Magneto tell him to remember. In Marvel's 2019 relaunch of its X-Men franchise,
Dawn of X, Sinister finds himself already bored with his new status on Krakoa, and decides to resume his schemes by utilizing a loophole in the Quiet Council's rules. To begin, he starts a file concerning
Franklin Richards, the mutant son of
Mister Fantastic and the
Invisible Woman.
Untold story in 1895 Immortal X-Men #8 (January 2023), which opens in 1895 London, revealed that the powers that Apocalypse gave Essex were slowly deteriorating and killing him, and to survive he needed to feast upon the flesh of innocent people who he killed, prompting two long-lived mutants,
Mystique (Sherlock Holmes/Raven Darkhölme) and
Destiny (Irene Adler) to confront and imprison him. Essex told the two women that Apocalypse did grant him the power to see the future, including major developments in the 20th and 21st centuries such as the escalation of the scale of war and the rise of the machines as the dominant beings on the planet. After Mystique secretly kills Essex in his cell, covering up her crime in her Holmes form, Destiny finds in a basement level, four human-sized tanks, each one marked with one of the four suits found on playing cards, smashed open and empty. One of them was the Mister Sinister that the X-Men know and continued the original's deep interests in mutants.
Ajak and
Makkari are shown to have Sinister as their prisoner. Sinister later informs Destiny about the Progenitor's judgment and that it has an "off switch". After the final judgment from the Progenitor, Sinister suggests making clones of Magneto to deal with the Progenitor. Sinister is with Ajak, Makkari,
Sersi, and Wolverine when Jean Grey informs them what is happening outside of the Progenitor. Sinister and Wolverine briefly end up in Grey's mind before being thrown out by the Progenitor.
The Moira Engine Emma Frost would later inform Mister Sinister that Moira MacTaggert is still alive and had been a mutant with timeline resetting abilities. Mister Sinister began using the Moira Engine by inserting his DNA codes into every mutant. This flaw was undone by Hope Summers. During the "
Sins of Sinister" storyline, Mister Sinister went through several Moira Engine resets with the latest one having his dreams realized where the corrupted Quiet Council of Krakoa conquered Earth and turned everyone into Mister Sinister-like beings. He tried to ascend only to learn that one his clones had done the job. The latest Moira was able to warn
Mother Righteous. A clone of
Rasputin IV from another timeline would later help to apprehend Mister Sinister, who was remanded to the Pit of Exile.
Fall of X and the Enigma Dominion While Sinister was trapped within the Pit of Exile, the genetic code he had implanted into the assassinated council members was nullified by
Forge, with one key exception; Professor X, whom Sinister had experimented on as a child. As Krakoa was destroyed by
Orchis, with mutantkind scattered, the part of Sinister within Xavier began looking for ways to overcome its host, and began piloting his body while he slept, simultaneously working on a way to fight the Sinister Dominion. After Xavier discovered the truth, Sinister revealed himself to him. He opened his mind to Xavier and managed to convince him not to kill himself and to work together with Sinister to stop the Dominion. Xavier and Sinister eventually discover the truth behind the four Nathaniel Essex Sinister clones; they were all created to absorb data, leading to the birth of a fifth "child" of Nathaniel Essex: an "apex AI" called
Enigma, the same force revealed that stands above all creation, and is coming to end
Eternity, the personification of the
multiverse. In truth, years ago, Essex decided the only way to defeat the coming machine supremacy was to join them, creating his own all-powerful artificial intelligence, which is where Enigma comes in. Enigma - using a Crown symbol similar to a card deck's King - is the 5th "child" of Essex, an AI that was able to reach Dominion outside time and space after all four clones attempted to reach said status, got incredibly close, and then failed to ascend. Professor X allows Rasputin IV to kill Mister Sinister. After Krakoa relocates to the
White Hot Room, Mister Sinister is revived by
the Five and uses Krakoa's Atlantic and Pacific branches to return the X-Men to Earth. At a S.H.I.E.L.D. Black Site in Green Point, Florida, the X-Force fight Mister Sinister and his Nasty Boys, who he has revived. After the Nasty Boys disintegrate, Sinister takes control of
Archangel. ==Powers and abilities==