Mister Sinister (Nathaniel Essex)

Nathaniel EssexMister Sinister

Immortal Victorian scientist and mutant obsessive, Mister Sinister uses his expertise in genetics to create the perfect mutant race, procuring his subjects by any means necessary.


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One of the greatest geneticists in the world, Nathaniel Essex is a formidable scientist and egomaniac who becomes immortal after being mutated by the ancient mutant En Sabah Nur, AKA Apocalypse. He spends his life researching genetics, cloning, and mutation, and mastering mutant abilities.


Evolution and Experimentation

A brilliant 19th century English biologist, Nathaniel Essex becomes obsessed with Darwin’s evolutionary theories after his son dies from numerous ailments and birth defects. Believing Darwin’s brilliance was shackled by excessive morality, the amoral Essex discovers humanity’ s capacity for mutation, stemming from untapped genetic potential he dubbed “Essex Factors.” Announcing his theories at a Royal Society meeting in London, Essex unveils a cadaver he had pieced together from human and animal remains. Horrified, the Society rejects Essex’s theories and ousts him. Unperturbed, Essex hires criminals called the Marauders to capture deformed humans for his experiments. They also try capturing the Apocalypse, but he enslaves them. Meanwhile, Essex exhumes his son’s corpse to further his theories, estranging his wife. 

Meeting Apocalypse, Essex discovers his mutant nature. When Apocalypse’s future enemies, the Clan Askani, sent the X-Man Scott Summers, AKA Cyclops, and Jean Grey, AKA Phoenix, into the past to oppose him, Apocalypse captures them, offering them as experiments if Essex agrees to join him. Conflicted, Essex decides to rededicate his life to his wife and unborn child, but a premature birth killed both mother and baby. Dying, his wife refuses his pleas for forgiveness, calling him “sinister” with her last breath. 

With nothing left, Essex swears fealty to Apocalypse, who genetically alters him into a superhuman being who rechristens himself “Sinister.” Apocalypse then tasks him with creating a pestilence, but Sinister was reluctant to devise a plague that would affect his life’s work. Instead, Sinister creates a techno-virus and betrays Apocalypse by infecting him with it. Cyclops and Phoenix thwart the weakened Apocalypse’s plot to assassinate Britain’s Queen, then return to their own time. Apocalypse lambasts Sinister for his betrayal, but retains his servitude as he returned to his regeneration chamber. 


Genetically Enhanced

Via genetic alteration by Apocalypse, Sinister possesses enhanced durability and an extended lifespan. He derives additional powers from other mutants’ genetic material, including telepathy, telekinesis, superhuman strength, concussive energy projection, and total control of his body at the molecular level, which allows him to shapeshift into other forms and to rapidly recover from most injuries. 

A genetics genius, a brilliant biologist, a skilled engineer and a master surgeon, Sinister is also a cloning expert. His costume, forged from an unrevealed metallic alloy, serves as body armor and can shift with him as he changes forms. He constructs numerous secret bases around the globe, all linked together via tesseract technology, wherein he stores the DNA samples he has gathered over the centuries. He also carries a cane equipped with a gem at the top, and contained in its sheath is a sword that glows red.


Coerced and Cloned Allies

Mister Sinister marries Rebecca Essex and together they have a son, Adam Stanislaus Essex, though he dies from birth defects. He dedicates his time and energy to studying mutation and performing amoral experiments, then he meets Apocalypse who offers him a partnership opportunity. Conflicted, he rededicates himself to Rebecca and their second unborn child. She dies in childbirth and leaves the world bitterly calling him “sinister”. He joins Apocalypse who genetically alters him.

Sinister hires a group of criminals, dubbing them the Marauders, to capture deformed humans for his experiments. He also coerces some of his allies including Remy LaBeau, AKA Gambit, who he ultimately employs to do his dirty work. But Gambit leaves his employ when the group slaughters the Morlocks.

As an expert in genetics and cloning, Sinister creates the clone Claudine Renko, AKA Miss Sinister, N2 (clone of Namor), and Madelyne Pryor by using Jean Grey, AKA Phoenix’s DNA. He founds the mutant team Marauders, a task force known as Nasty Boys—a gang of mutant followers—and is formerly affiliated with Weapon X, the Third Reich, and the Royal Society.


Mutant Enemies

After Sinister experiments on mutants Cyclops and his brother Alex, AKA Havok, and toys with their bloodline, he makes an enemy of them and their fellow X-Men and later Havok’s team, X-Factor.


6'5" (variable)


285 lbs.




Red, no visible pupils (variable); formerly brown


Black (variable)

Universe, Other Aliases, Education, Place of Origin, Identity, Known Relatives, Powers, Group Affiliation
  • Universe

  • Other Aliases

  • Education

  • Place of Origin

  • Identity

  • Known Relatives

  • Powers

  • Group Affiliation

A Sinister Story

After attending Darwin’s funeral in 1882, Sinister relocated to New York and established himself as leading obstetrician Dr. Nathan Milbury. His patients unknowingly provided an abundance of genetic material to study, especially Amanda Mueller, a long-lived mutant who inspired Sinister to seek eternal life. He began secretly using her as a birthing factory for his experiments; however, she suffered a series of miscarriages before finally bearing a son, and was accused of murdering her miscarried children in what came to be known as the “Black Womb” affair. This drove her husband Daniel away with their only surviving son. Ultimately, she was acquitted thanks to “Milbury’s” testimony, but his public appearances attracted mutant time-travelers Gambit and Jacob Gavin Jr., AKA Courier’s attention. Learning that Courier was a shape-shifter, Sinister captured him and members of Gambit’s New Orleans Thieves’ Guild. In exchange for their freedom, Sinister took a cell sample from Courier, which he used to gain shape-shifting powers. Gambit later had Sinister restore his powers to their full potential to allow himself and Courier to return to their own time.

Reawakened by Sinister in 1899, Apocalypse had adapted his molecular structure to control the techno-virus; he released Sinister from his service, swearing enmity against him. Unable to defeat Apocalypse, Sinister plotted to create a being that could. In 1915 England, Sinister unlocked Jacob Shaw’s latent mutant shapeshifting ability. Sinister then wandered the globe searching for more mutants. In Russia he revealed so-called mystic Grigory Rasputin was a mutant, and bade him take many partners to forge a strong bloodline. Before dying, Rasputin magically transferred his essence into his unborn children to ensure his eventual return. In the 1920s, Sinister worked at Oxford University and took an interest in genetics student Herbert Edgar Wyndham, the future High Evolutionary. In the 1930s, Sinister posed as a wealthy Hollywood socialite. Identifying radio comedienne Faye Livingstone as a mutant, Sinister romanced her, then imprisoned her for weeks as he subjected her to degrading examinations before finally setting her free.

In 1944, Sinister worked as a Nazi scientist alongside geneticist Josef Mengele at Auschwitz. There, he earned the nickname “Nosferatu” for his pale complexion and his habit of trading sweets to children in return for a drop of their blood. Sinister was authorized to use any prisoners he desired for his experiments. One young prisoner, Max Eisenhardt (the future Magneto), avoided Sinister by becoming a Sonderkommando, cleaning out the gas chambers where he found Sinister’s test subjects’ twisted bodies. Later Sinister obtained a sample of Namor McKenzie, AKA Namor the Sub-Mariner’s blood after Namor was injured battling Wolfgang von Strucker, AKA Baron Strucker, and Wilhelm Lohmer, AKA Master Man. Sinister employed disgraced United States soldier John Greycrow (later Scalphunter) to secure Jewish prisoners used in creating a Namor clone, Experiment N2. When the Invaders infiltrated Sinister’s base, he fled as Steve Rogers, AKA Captain America, defeated N2. Sinister’s base was cleaned out by the Howling Commandos and Professor Andre Thorton, who discovered Sinister’s journal who used it to accelerate the Weapon Plus Program’s formation. Sinister subsequently used Apocalypse’s tesseract technology to establish a massive laboratory in a pocket dimension accessible via numerous locations around the globe. 

In 1946, Sinister revisited Müeller after she became involved in the U.S. government’s Project: Black Womb. He then worked at the Alamogordo research facility at Milbury to create a fail-safe in the event of his death by encoding his genetic material into his fellow scientists’ children who included Cain Marko, Sebastian Shaw, Carter Ryking and Charles Xavier, AKA Professor X, and created the Cronus device as this fail-safe’s activator. Later, Sinister returned to Oxford, where his students included Moira MacTaggert and Xavier.

Sinister subsequently established Sage, Nebraska’s State Home for Foundlings, where he manipulated its children’s development for decades. Learning of the young Summers brothers, Scott and Alex, Sinister drugged the hospitalized Scott, making the boy seem comatose, then had both boys transferred to his orphanage. He arranged for Alex to be adopted away from Scott, though he kept close track of him. Testing Alex’s potential, Sinister incited a local bully to attack him, forcing Alex to defend himself with his mutant energy powers; Sinister then placed a mental block on Alex’s ability to manifest his power. At some point during this time, Sinister grafted a sample of Alex’s DNA onto Ahmet Abdol, catalyzing his transformation into the Living Monolith. Returning to Scott, Sinister experimented on him for a year, buried Scott’s memories of this period, and placed mental blocks on Scott’s ability to use his power against Sinister. He subsequently posed as young orphan Nate to monitor Scott’s progress more closely. When a family planned to adopt Scott, Sinister arranged a fatal accident for them. Eventually, Sinister realized that Scott would never control his powers, so he gave Scott glasses fashioned from ruby quartz, the only substance Scott’s optic beams could not penetrate. Sinister hoped to keep Scott for himself, but eventually Xavier recruited Scott as the first X-Man known as Cyclops. Sinister schemed to reclaim Scott and to control the young mutant Jean Grey (later Phoenix) but she, too, joined the X-Men, eventually becoming Scott’s lover.

Obtaining Jean’s DNA, Sinister created a clone he named Madelyne Pryor, and programmed her to love Scott. Sinister hoped Pryor would lure Scott away from the X-Men and bear a child with both Scott’s and Jean’s genetic potential to use against Apocalypse. After artificially aging Pryor, Sinister was disappointed when she did not manifest any mutant abilities; however, an aspect of the cosmic Phoenix Force soon empowered her. Following Jean Grey’s apparent demise, Sinister gave Pryor false memories of life as a pilot and arranged for her to work for Scott’s grandparents in Alaska. She soon met Scott, unwittingly putting Sinister’s plan into action. Before long, Scott and Madelyne were married and had a child, Nathan, unaware that Sinister was monitoring them in the guise of Mike Milbury, neighbor to Scott’s grandparents.

At some point, Gambit sought Sinister’s aid in controlling his powers. Sinister removed some brain tissue to limit Gambit’s abilities, then forced Gambit into his service by retaining the portion. After Sinister learned that his research had been co-opted by Henry McCoy, AKA Dark Beast, from Earth-295 (“Age of Apocalypse”) who used it to create some of the Morlocks, he sought to destroy this corruption of his life’s work and had Gambit form a new incarnation of the Marauders. Gambit helped the Marauders access the Morlock tunnels, but he was horrified when they began slaughtering the Morlocks. Unable to stop them, Gambit accepted Sinister’s “payment” of his excised brain tissue, then left Sinister’s service.

After Scott and a returned Jean reunited as X-Factor members, Sinister chose to cut his losses and destroy Madelyne before she exposed him. He eliminated all records of her existence, kidnapped baby Nathan and sent the Marauders to assassinate Madelyne, but the X-Men saved her. Soon after, the demon N’astirh corrupted Madelyne into becoming the Goblin Queen as part of a demonic invasion of New York City. She confronted Sinister regarding her true origins, proving too powerful for him to control, and reclaimed her son, intending to use him as a demonic sacrifice, but the X-Men and X-Factor defeated her. Sinister then attacked Jean, seeking to destroy her memories, but Betsy Braddock, AKA Psylocke, repelled him. The heroes confronted Sinister, and Cyclops overrode his mental blocks to seemingly destroy Sinister with a massive optic blast. Sinister survived thanks to his malleable form.

At some point, he also created a female clone of himself, named her Claudine Renko, AKA Sinister Claudine Renko, and sent her out into the world. He also learned of the Shi’ar warrior Adam-X, AKA X-Treme, who was apparently connected to the Summers family. Afterwards, Sinister sought to recapture baby Nathan; however, upon realizing Sinister’s plan, Apocalypse infected Nathan with a techno-organic virus that forced Cyclops to send him to Earth-4935’s 40th century to be cured, from which Nathan returned as the mutant soldier Cable.

Forming the Nasty Boys, Sinister manipulated Senator Steven Shaffran, inciting conflict with the new government-sponsored X-Factor led Havok. Sinister bargained with Cable’s clone Stryfe for the future genetic material of the Summers family in exchange for Scott and Jean. Impersonating Apocalypse, Sinister had the Horsemen capture Scott and Jean, trading them to Stryfe’s Mutant Liberation Front for a canister supposedly containing the material he sought. Sinister then betrayed Stryfe by leading the X-Men to him, but was double-crossed when the canister proved to be seemingly empty, though it actually unleashed the deadly Legacy Virus. Seeking to preserve his work, Sinister alerted Scott to the Virus’ threat and also let slip that Scott might have more than one brother before Apocalypse’s Dark Riders confronted them, prompting Sinister to leave. 

Later, Sinister met with Cable’s son Tyler before confronting Cable and revealing to him the truth of his origins. He then sought out Legacy Virus victims to study the disease, hoping to cure it so that it would not further disrupt his work. His search led him to Melody Jacobs, AKA Threnody, who became his new assistant. Learning that X-Treme was on Earth, Sinister hired the assassin Arcade to test him.

Sinister subsequently employed the Gamesmaster and his Upstarts to retrieve the DNA matrix of the apparently deceased mutant Kevin MacTaggert, AKA Proteus. Upstarts operative Siena Blaze was thwarted by British super-team Excalibur, but did retrieve cell samples of Rachel Summers, Scott and Jean’s daughter from an alternate timeline (Earth-811), which placated Sinister. Later, Sinister aided Havok and his lover Lorna Dane, AKA Polaris, against ex-Marauder Malice by seemingly destroying her. Meanwhile, seeking to learn what Sinister had discovered regarding the Legacy Virus, the X-Men encountered Threnody, who revealed that she was secretly opposing Sinister and proved it by destroying his genetic storage banks. Soon after, Sinister offered the X-Man Kurt Wagner, AKA Nightcrawler, the opportunity to clone his recently deceased teammate Piotr Rasputin, AKA Colossus. Nightcrawler refused, and destroyed Sinister’s Colossus DNA sample.

Subsequently, Tyler sought to become heir to Apocalypse’s power as Genesis and resolved to destroy Sinister. Genesis uncovered Sinister’s relationship with Faye Livingstone, and threatened to kill her unless Sinister showed his weakness by admitting his love for her. Sinister refused, despite Faye’s admitting her true feelings before she died.

Suspecting that his work had again been perverted, this time in developing Genosha’s mutate bonding process, Sinister sought to uncover the culprit by clandestinely aiding the Genoshan rebellion. With Cable’s assistance, Earth-295’s Sugar-Man was revealed as the perpetrator and defeated. Through the Sugar-Man, Sinister became aware of Earth-295’s Nate Grey, AKA X-Man, an alternate Cable never infected with the techno-virus. Running out of test subjects, Sinister created a virus that spontaneously mutated humans, and tested it on commuter train passengers. Opposed by the X-Men Bishop, Gambit, and Beast (secretly the Dark Beast), Sinister captured them and learned of Nate Grey’s home reality. Gambit fooled Sinister into freeing him and destroyed Sinister’s laboratory, robbing him of his research. 

Sinister ultimately captured Nate Grey despite X-Force’s interference, but failed to coerce Grey into his service before the psionic being Onslaught took Grey. Sinister next offered to cure Cable of his techno-virus infection. When Cable refused, Sinister sent the disguised Marauders to attack Cable, whom he seemingly freed from the virus, allowing Cable to defeat the Marauders easily; however, his “cure” proved temporary. Subsequently, Sinister restored Victor Creed, AKA Sabretooth’s health after Apocalypse forcibly removed the Adamantium bonded to Sabretooth’s skeleton. He then seized and modified a device created by the High Evolutionary to devolve mutants into ordinary humans, intending to use the entire planet as an experiment in accelerated mutation. The X-Men defeated Sinister, and the High Evolutionary reversed the device’s effects. 

The race of super-mutants called the Neo learned of Sinister’s involvement in the depowering, which devastated their community, and swore to destroy him. They destroyed Sinister’s installations, seemingly killing Sinister. He survived yet again.

Later, as Dr. Robert Windsor, Sinister joined the revived Weapon X Program and worked at their “Neverland” mutant concentration camp where he “saved” imprisoned mutants for use in his experiments. After the Weapon X Program was fragmented, “Windsor” became head of the Center for Homo Superior Research and Medical Care. Megacorp head Michael Grand subsequently hired Sabretooth to eliminate Sinister, allegedly an act of revenge for Sinister’s having victimized him during World War II. Sabretooth defeated Sinister’s latest creations, an army of super-mutants, after which Grand confronted Sinister and revealed himself to be John Sublime, head of the Weapon Plus Program, who traded Weapon X’s mutant files to Sinister in exchange for the super-mutants. Sinister then learned that Rasputin was trying to return, but his essence was fragmented across his family’s bloodline. With his own powers failing, Sinister sought to hasten the process and began killing Rasputin family members, deciding that Mikhail Rasputin would be the last survivor through whom Grigory would return. Rescuing Mikhail from self-imposed exile, Sinister mentally coerced him into helping bring about Grigory’s return but was opposed by Mikhail’s brother, the resurrected Colossus. Ultimately, Mikhail turned against Sinister and exiled himself in the extradimensional Dark Zone to prevent Grigory’s return. 

On “M-Day,” when many of Earth’s mutants became human, Sinister seemingly lost most of his genetically-obtained mutant powers. He later learned of the impending birth of the first mutant child since “M-Day.” In an effort to acquire the child he assembled a new group of Marauders, including former X-Men Gambit and Shiro Yoshida, AKA Sunfire, and sent them to slay precognitives in order to prevent the X-Men from foreseeing the event. He also sent them to acquire the blind mutant seer Irene Adler, AKA Destiny’s diaries, but Gambit destroyed them in a clash with the X-Men. After the Marauders obtained the child, Sinister was betrayed and killed by the Marauders’ leader, Raven Darkhölme, AKA Mystique, who sought to use the child to heal the mind of her daughter, the X-Man Anna Maria, AKA Rogue

Upon his death, the Cronus device activated and Sinister’s genetic material activated within Xavier; however, Müeller sought to become Sinister’s new vessel and tried to kill Xavier and the other Alamogordo children, though she failed and was seemingly slain by Sinister. Aided by Gambit, Shaw destroyed the Cronus device while Xavier defeated Sinister. Though Sinister appears to be dead, Shaw has since recruited Sinister’s female clone Claudine into the Hellfire Club as “Miss Sinister.” Miss Sinister was then drawn to a machine that implanted Sinister’s consciousness into her but she attempted to escape by transferring her consciousness into Laura Kinney, AKA X-23. X-23, with Gambit’s help, drove the invasion out, and Sinister possessed another clone. 

Later, Sinister assaulted and stole the head of the massive alien Dreaming Celestial of the Celestials in San Francisco. He used it to assemble a “Sinister World’s Fair” made up of copies of himself, in an attempt to make Earth a heaven by creating a new species, beyond Homo superior. He was able to create these carbon copies thanks to his experiments on the Phalanx, a race of techno-organic hybrids who could absorb others into their hive-mind. He succeeded but faced Cyclops’ Extinction Team in an all-out battle for the head as the Celestials were headed for Earth. While Sinister revealed his evolutionary plans, he also mind controlled the X-Men except Emma Frost as her diamond form protected against such mental invasions. Shot in the head by Hope Summers, Sinister fell though his many other Sinister copies declared that he was unkillable since they were a hive mind. The battle raged and Sinister apparently committed suicide but another Sinister iteration returned to his labs that housed the lonely Phalanx that he left behind, and he destroyed it. 

He then spent time underground and created a city underneath Anchorage, Alaska. His city was Sinister London, inspired by 19th century London. He ruled the city over his clones and powered it using Celestial energies. He plotted to use the returned Phoenix Force, and luring the newly created Phoenix Five to his city, he removed and divided the Force into six clones of Madelyne Pryor. When Emma Frost, one of the Phoenix Five, telepathically communicates with the Phoenix Force, she convinced it to leave and fulfill its purpose, and it does so, but not before incinerating Sinister, his clones, and his city.

Though, in Sinister fashion, he survived and hid dormant in the mind of Kate Kildare, Cyclops’ Public Relations Head. After the Phoenix left earth, he seized control of her body and threatened Cyclops to take him on.

Sinister’s next attempt at creating a superior species occurred after Terrigen Mist was released into Earth’s atmosphere. He captured unwilling participants to co-mingle Inhuman and Mutant DNA. He ended up creating a clone of recently deceased Cyclops, and while the X-Men fought it off, Colossus battled Sinister. Though the clone was inviable and exploded, and Colossus’ sister Illyana Rasputin, AKA Magik, subdued the egomaniac. The X-Men had S.H.I.E.L.D. detain Sinister and his Marauders.

When Magneto and Xavier approached Sinister offering him a deal for to create a database of his mutant DNA material in exchange for their own genetics, Sinister refused. Though he was immediately slaughtered by another Sinister interested in taking the deal. Xavier repressed the meeting so that Sinister would go about enacting the deal without knowing it. Sinister was later invited to the mutant nation-state and island Krakoa, founded by Xavier, Magneto, and Moira X. They asked him to join the Quiet Council alongside Exodus and Mystique to represent the more villainous in mutant society. Though Sinister lost interest and started looking at the Omega-Level Mutant Franklin Richards to restart his mutant DNA harvest.

Mister Sinister
Essential Reading
Mister Sinister
Marvel’s resident expert geneticist. Dr. Nathaniel Essex’s long history of experimenting on mutants is as horrifying as his origin and self-made mutations. In his quest for a perfect mutant race, Essex procures his subjects by any means, earning him a name as evil as his intent - Mister Sinister.