Published November 18, 2022

Meet Mister Sinister, the X-Men's Clone-Creating Nemesis

Who is Mister Sinister? Meet Nathaniel Essex, a twisted scientist with an affinity for clones, before he disrupts the X-Men’s future in ‘Sins of Sinister.’

As one of Marvel’s most dangerous mutants, Mister Sinister has menaced the X-Men for years. Despite manufacturing some of the X-Men’s greatest tragedies, he played a crucial role in making the mutant paradise Krakoa possible and has since worked alongside leaders like Charles Xavier and Emma Frost… but now, Sinister’s endless schemes and devastating secrets could doom the X-Men’s future.

As he gears up to unleash the SINS OF SINISTER on the Marvel Universe, let’s take a closer look at Mister Sinister and how decades of villainy forged him into one of the ultimate mutant threats.


After lurking in the shadows for months, Mister Sinister fully debuted as the mastermind behind the Marauders – the assassins who perpetrated the “Mutant Massacre” – in UNCANNY X-MEN (1963) #221 by Chris Claremont and Marc Silvestri. But long before that comparatively recent debut, Mister Sinister began life as Nathaniel Essex, a 19th century scientist. Driven by the death of his ill child, Essex was obsessed with the theory of evolution and predicted the emergence of mutants. His cruel experiments, which shattered moral and ethical boundaries in the name of science, eventually drew the interest of Apocalypse

In FURTHER ADVENTURES OF CYCLOPS AND PHOENIX (1996) by Peter Milligan and John Paul Leon, Essex encountered a time-traveling Cyclops and Jean Grey. That encounter sparked a lifelong fascination with both of those X-Men and briefly pushed the scientist to rededicate himself to his surviving family. But after discovering his twisted experiments, Essex’s wife Rebecca cursed him and called him “sinister” moments before dying. The grieving Essex was then recruited by Apocalypse and genetically modified to be functionally immortal, after which he took the name Mister Sinister.

After turning against Apocalypse, Sinister continued to conduct his cruel research around the Marvel Universe. Thanks to a time-traveling Gambit, Sinister gave himself the shape-changing powers of the mutant criminal Courier. Through his early research into mutant genetics, Sinister encountered future heroes and villains like Wolverine, the High Evolutionary, and Destiny, and he worked alongside Charles Xavier’s father at the Project: Black Womb genetic research base.  

With his focus on emergent mutant children, Mister Sinister took a keen interest in a young Cyclops and Havok after the apparent death of their parents. As the founder of the orphanage that took in the Summers siblings, Sinister manipulated and monitored the lives of both boys, even developing the ruby-quartz lenses that contain Cyclops’ optic blasts. Similarly, Sinister also helped a young Remy LeBeau control the mutant powers he would later use as Gambit.


Having gathered genetic samples from numerous subjects throughout his extended life, Sinister also experimented extensively with clones. Sinister even staffed Bar Sinister, a private island research facility, entirely with modified clones of himself. Later on, when Xavier and Magneto approached Sinister about expanding his collection of mutant genetic material, a mutant clone of Sinister with the powers of the late Thunderbird emerged as the dominant Sinister in POWERS OF X (2019) #4 by Jonathan Hickman and R.B. Silva.

Sinister also created a clone of Jean Grey known as Madelyne Pryor. After Jean seemingly died in “The Dark Phoenix Saga,” the Phoenix Force sent a spark of life into Pryor. Sinister even orchestrated a meeting between her and Cyclops in UNCANNY X-MEN (1963) #168 by Chris Claremont and Paul Smith. Cyclops and Madelyne soon married and had a child named Nathan, who would grow up to become the time-traveling mutant known as Cable. Nathan’s birth marked the culmination of Sinister’s research into the Summers and Grey genomes and his efforts to create a mutant who would be powerful enough to kill Apocalypse.

After seeing traces of his research in their genes, Sinister turned his fury towards the Morlocks, an outcast group of sewer-dwelling mutants with bizarre powers and appearances. Sinister had Gambit – who still owed Sinister for stabilizing his powers – gather Sabretooth, Vertigo, and other lethal mutants to form the Marauders, although LeBeau did not join the team. In the seminal “Mutant Massacre” storyline, the Marauders slaughtered most of the Morlocks starting in UNCANNY X-MEN (1963) #210 by Chris Claremont and John Romita Jr. In the attack, the Marauders lost some of their own, but seriously injured the X-Men’s Angel, Kitty Pryde, Colossus, and Nightcrawler in the process.

When the original Jean Grey was found alive, Sinister kidnapped baby Nathan, kicking off the events that led to the “Inferno” crossover. After Madelyne Pryor made a deal with the demon N’astirh to find her son, she met Sinister, learned about her status as a clone, and transformed into the villainous Goblin Queen. Blaming Cyclops, Jean, and the X-Men for her troubles, an unhinged Madelyne attacked New York with her demonic powers. After the X-Men, X-Factor, and the New Mutants defeated her, Sinister and the Marauders confronted the heroes and destroyed Xavier’s Mansion. Once Cyclops realized how Sinister had manipulated his life, he unleashed the full extent of his power on Sinister in X-FACTOR (1986) #39 by Louise Simonson and Walt Simonson.


Throughout his subsequent encounters with the X-Men, Sinister revealed he also had immense telepathic powers, started working with the Nasty Boys, and even helped the X-Men on a few occasions – especially with a mutant plague called the Legacy Virus. But after most of the world’s mutants lost their powers at the end of HOUSE OF M (2005), Sinister reassembled the Marauders to capture the newborn mutant Hope Summers during X-MEN: MESSIAH COMPLEX (2007)

Sinister began transferring his consciousness between various bodies with increasing regularity, even creating a small city populated by his clones in UNCANNY X-MEN (2011) #1 by Kieron Gillen and Carlos Pacheco. After recreating 19th century London under Alaska through similar means, Sinister continued gathering genetic samples from new generations of X-Men, tried to combine Inhuman and mutant DNA, and began experimenting on a new generation of Morlocks again.


When Xavier, Magneto, and Moira MacTaggert founded the island nation Krakoa, Sinister’s database of mutant genetics played a critical role in establishing the process for resurrecting dead mutants in new bodies. Accordingly, Sinister was named a member of Krakoa’s Quiet Council, a group of 13 diverse mutant leaders that governed the island, in HOUSE OF X (2019) #6 by Jonathan Hickman and Pepe Larraz

While Sinister has governed the island alongside several X-Men and former X-villains, he has still conducted his own twisted research in secret, with a particular interest in combining the powers of multiple mutants into chimeras. Initially, Sinister coerced Psylocke, the telepathic mutant formerly known as Kwannon, into secretly working with him in FALLEN ANGELS (2019) #1 by Bryan Edward Hill and Szymon Kudranski. Sinister was then given direct oversight over a group of habitually violent or unpredictable mutants like Psylocke, Havok, and Wild Child in HELLIONS (2020) #1 by Zeb Wells and Stephen Segovia. Despite the team’s official status, Sinister largely used it for his personal purposes, such as destroying evidence of an old lab and helping secure a new secret cloning lab.

Along with the rest of the Quiet Council, Sinister learned about Moira’s mutant power, which allowed her to reset the timeline after her death and be reborn with memories of her previous lives. While she used this to guide the development of Krakoa, Moira’s ability only allowed her to be reborn 10 times. 

Soon enough, Sinister secretly found a way to exploit this power, as revealed in IMMORTAL X-MEN (2022) #1 by Kieron Gillen and Lucas Werneck. Sinister created several clones of Moira and regularly uploaded relevant knowledge into their minds. When Sinister wanted to change an event, he killed a Moira clone, which reset time to the moment he created her and allowed him to learn how events played out in the abandoned timeline. Sinister has reset the timeline 26 times, allowing him to survive the Celestial Progenitor’s attack in A.X.E: JUDGMENT DAY (2022).

While Sinister has been focused on his schemes, a new villain, Doctor Stasis, has stepped forward with radical claims about Sinister’s past. As a leader in the anti-mutant organization Orchis, Stasis has worked against Krakoa and even leaked knowledge of its resurrection protocols to The Daily Bugle. After a brutal fight with Cyclops, Stasis was unmasked, which revealed he was identical to Sinister – except for a black club symbol on his forehead in place of Sinister’s signature red diamond symbol. Stasis said he was the original Nathaniel Essex and added that he had not tainted his biology with mutant genes like Sinister. With little regard for mutants, Stasis said mutantkind’s future was in space and that he had plans for a “fall of the mutants" in X-MEN (2021) #12 by Gerry Duggan and Pepe Larraz.

Although Sinister prides himself on his schemes and secrets, he was shocked to learn about the existence of Stasis… and with SINS OF SINISTER on the horizon, Sinister’s response could completely rewrite the X-Men’s future.

The road to SINS OF SINISTER has already begun! Pick up IMMORTAL X-MEN (2022) #8, on sale now, and then IMMORTAL X-MEN (2022) #9, on sale December 7, to find out more!

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