Few villains are as horrifying as Mister Sinister. Writer Chris Claremont and artist Marc Silvestri introduced the character in Uncanny X-Men (Vol. 1) #221 as the mysterious leader of the Marauders. Claremont, who'd grown tired of constantly returning to Magneto as a major antagonist, sought to create a new archnemesis for the X-Men, and Sinister quickly established himself as an A-list foe, seemingly incapable of passing away, much less being defeated. The more Sinister popped up, the more the mysterious figure was illuminated but, as fans would learn, there was always more to Sinister. The writers went deeper and deeper into Sinister's backstory -- like Wolverine, he seemed to have been everywhere during the past century. We've decided to cull the 20 most astonishing facts from Mister Sinister's storied history.

After a meeting with Apocalypse during the 1800s, Nathaniel Essex was granted immortality. Reborn, Essex now referred to himself as "Mister Sinister", and set to work on creating a race superior to mutankind. His relentless research brought him into contact with several historical figures, as well as tons of icons of the Marvel Universe. In fact, it turns out that Sinister had his hand in the origin story of some of Marvel's most powerful heroes and villains -- including the High Evolutionary, Cable, and Madelyne Pryor. As a super genius with a total disregard for moral constraint, there was little to stop Sinister from engaging in whatever experimentation he desired. He's used his ruthless dedication toward scientific truth to excuse any number of atrocities against humankind and mutantkind -- which makes his occasional acts of goodness all the more baffling. Here are 20 weird facts about Mister Sinister.

20 RECEIVED ADVICE FROM CHARLES DARWIN

The man who would become Mister Sinister, Nathaniel Essex, was a 19th-century biologist living in England. One of his most esteemed colleagues was Charles Darwin, the biologist who came up with the theory of evolution. Despite being obsessed with Darwin's theory, Essex thought the man's genius was encumbered by a moral code.

Essex believed that science was beyond good and evil and that scientific truth ought to be served by any means possible. After his son passed away, Essex dove even deeper into his work. Upon finding that his contemporary's mind was slowly deteriorating, Darwin suggested that Essex seek out psychiatric help.

19 TAUGHT PROFESSOR X

Another character that Sinister would meet with in their youth was Charles Xavier. Even with young Magneto on his trail, hunting those who wronged him, Sinister escaped the fate of many of his comrades. Following WWII, Sinister took part in various research projects before landing a teaching position at Oxford University.

He lectured on Biophysics and Genetics and took an interest in two of his most talented students, Charles Xavier and Moira Kinross. Xavier sensed that something was off about his professor on account of not being able to read Essex's mind, but Xavier had no idea just how nefarious his professor was.

18 WORKED ON WEAPON X

Considering how little regard Sinister has for ethics, it shouldn't come as a surprise that he had a hand in the infamous Weapon X Program. Working under the alias of Dr. Robert Windsor, Sinister lent his genius to the staff responsible for implanting adamantium into Wolverine's body.

Unbeknownst to this colleagues, Sinister freed multiple prisoners of the program. Of course, it was only so Sinister could take them back to his own private laboratory and conduct experiments on them. These subject would come to be known as the Children, a group of uber-powerful beings that would plan to conquer the world decades later.

17 MASTERMINDED CABLE'S DESTINY

Sinister went to extreme lengths to try to defeat Apocalypse, whom he was indebted to. Finally, Sinister discovered the right mutant to do it -- he just had to ensure the mutant's birth. Sinister organized the birth of Cable by setting up Cyclops with Madelyne Prior, a clone of Jean Grey.

The two had Cable, who, even as a baby, promised to be one of the most powerful mutants of all-time. Apocalypse was awoken when he sensed the birth of the powerful mutant, eventually leading Cable to be raised in the future. Much later, Cable finally fulfilled his destiny and destroyed Apocalypse --the destiny that Mister Sinister had secretly organized for him.

16 CREATED A CARNAGE-KRAVEN HYBRID

Among all of Sinister's creations, none are quite like Xraven. In X-Men/Spider-Man (Vol. 1) #1, it was revealed that at one point Sinister had hired Kraven the Hunter to retrieve DNA samples of the original X-Men. Later, Sinister got his hands on the Carnage symbiote. From a mixture of Kraven's DNA, the X-Men's DNA, and Carnage's DNA, Sinister created Xraven.

The creature was kept in a tank until Sinister needed him. That time came in the wake of M-day when Sinister sent Xraven on a mission to get DNA samples from every last mutant. After procuring the samples, Xraven destroys them and declares his freedom from Sinister.

15 NICKNAMED NOSFERATU

Mister Sinister joined forces with the wrong side during World War II, working as a scientist at Auschwitz. Sinister's pale complexion earned him the nickname 'Nosferatu' from the children held captive at the camp. However, Sinister turned out to be way scarier than the title character of the 1922 silent horror movie.

Sinister even scared the German officers as he seemed to have a supernatural hold over them. "Nosferatu" picked out prisoners, seeking out subjects for experimentation, though some believed him to be freeing prisoners. The young Magneto, who was held prisoner there, was wise to Sinister's intentions, and carefully avoided selection.

14 EXPERIMENTED ON HIS SON

Before he even became Mister Sinister, Essex tossed aside morality for the sake of scientific progress. His most egregious act? Digging up his son who had passed and experimenting on him. The stunning reveal took place in The Further Adventures of Cyclops and Phoenix, a story that involved the two mutants traveling back in time in an effort to prevent Essex's transformation into Mister Sinister.

Cyclops and Phoenix ended up failing, but not before discovering that Essex had always been twisted and that Apocalypse didn't make him that way. In addition to experimenting on his son, Essex hired thugs to capture people off the street and bring them down to Essex's lab.

13 TECHNICALLY NOT A MUTANT

Sinister is armed with a number of mutant abilities, though he himself is not technically a mutant. Rather, when Apocalypse transformed Essex into Mister Sinister, Essex acquired mutant traits, making him a mutate. Essex's initial powerset was exclusively the gift of Apocalypse and included immortality and various psychic abilities.

But throughout the decades, through countless interactions with other mutants, Sinister has acquired a number of other abilities, including teleportation, healing factor, generation of concussive blasts, and force field creation. One the most useful abilities that he's picked up is shape-shifting, which allows him to consistently escape punishment for his crimes.

12 FEUDED WITH COLOSSUS' GREAT GRANDFATHER

While Sinister's greatest nemeses within the X-Men are consistently Cyclops and Gambit, Sinister does have it out for Colossus. As with most of Sinister's vendettas, Sinister's hatred for Colossus is indirect, having been born way before the steel mutant's birth. In X-Men: Colossus Bloodline #1, fans discovered that Sinister feuded with Colossus' great-grandfather, Grigory Rasputin, motivating Sinister's initiative to eliminate Grigory's descendants.

Sinister's plan was to get rid of all of Grigory's descendants save for one, facilitating the reincarnation of Grigory, which Sinister needed to stabilize his fading powers. Colossus and his brother Mikhail caught on to Sinister's plot and were able to stop Sinister's attack on the Rasputin bloodline.

11 INDEBTED TO APOCALYPSE

After stumbling onto Apocalypse during the 19th century, Essex decided to make a deal with the devil. Essex and Sinister agreed to work together toward the birth of a superior species. Essex was then transformed by Apocalypse into Mister Sinister, shedding the last of his humanity and gaining mutant abilities.

In return, Sinister was expected to create a plague that would wipe out humankind -- or else. However, soon after gaining his abilities, Sinister turned on Apocalypse, aiming the plague he created exclusively at the ancient mutant. Apocalypse, unharmed, let Sinister off with a warning since he respected Sinister's sign of defiance.

10 OBSESSED WITH THE SUMMERS' BLOODLINE

Sinister has been obsessed with Scott Summers' bloodline since the 1800s. After Cyclops ran into Sinister several times in the present day, Scott couldn't figure out why Sinister wouldn't leave him and his family alone. Seeking to uncover the reason for Sinister's obsession and to prevent him from every toying with their family, Cyclops and Jean Grey traveled back in time to the 19th century.

In The Further Adventures of Cyclops and Phoenix, Scott and Jean arrived around the time that Apocalypse had awakened and met Essex. After several fights, Sinister realizes that Scott has already known Sinister, sparking his curiosity and motivating his obsession with Cyclops and his kin.

9 MASTER OF TIME PARADOXES

Sinister has been entangled in more than his fair share of time paradoxes. One of the most mind-boggling paradoxes that Sinister has to do with his strange obsession with Cyclops and his bloodline. After being inexplicably haunted by Sinister for years, Cyclops and Phoenix traveled into the past in an attempt to prevent Essex from becoming Mister Sinister.

However, Cyclops' encounter with Sinister during the 19th century only served to spark Sinister's interest in the Summers' bloodline. Furthermore, Sinister determined that Cyclops was the best father for the mutant destined to defeat Apocalypse -- Cable. And no one is responsible for more time-traveling paradoxes than Cable.

8 CLONES HIS ENEMIES

In his perpetual aim to create a superior race, Sinister has created countless clones. Many of these clones have been of his enemies. One of the earliest instance of this preoccupation was when Sinister cloned Namor, the Sub-Mariner. Calling his clone N2, he unleashed his evil Namor on the Invaders.

Luckily, Captain America was able to take out N2, sending Sinister back to the drawing board. In recent years, Sinister has presented a clone of Cyclops after the original perished. The clone was incredibly powerful and none of the X-Men seemed capable of stopping its rampage. Fortunately for the X-Men, the clone proved to be unstable and collapsed before it could wreak too much damage.

7 INSPIRED THE HIGH EVOLUTIONARY

During the '20s, Sinister met with Herbert Wyndham -- the man who'd become the High Evolutionary. Sinister's work had been a huge influence on Wyndham, inspiring his dream to crack the genetic code. A shadowy figure, strongly suggested to be Sinister, later handed Wyndham what he needed to fulfill his dream.

The transaction activated his transition into becoming the High Evolutionary where he'd create various hybrid species, even playing a key role in Jessica Drew's transformation into Spider-Woman. The High Evolutionary would grow more powerful and daring as the years went by, culminating in his creation of Counter-Earth where he played god in a world of his creations.

6 HIS UNUSED BACKSTORY

Mister Sinister's creator, Chris Claremont, originally had a much different backstory for the character. Claremont introduced Sinister as a major new antagonist after he grew tired of constantly going back to Magneto and the Brotherhood of Evil Mutants. Essex was originally meant to be an 11-year old peer of Cyclops at the orphanage where he was raised.

However, Essex was really ancient being stuck in a boy's body. In order to make inroads in the criminal community, Essex created the shadowy persona of Mister Sinister. The unused backstory does much to explain Sinister's childish sounding name, as well as his interest in Cyclops.

5 THE ULTIMATE HYPNOTIST

The Ultimate MU Mister Sinister is vastly different from his 616 counterpart. The Ultimate version of Nathaniel Essex worked under Norman Osborn and acquired superpowers after he experimented on himself. Essex's new abilities made him a master hypnotist, capable of hypnotizing anyone to do his bidding.

After the experiment, Essex also found himself having hallucinations of an all-powerful being called Apocalypse. At Apocalypse's behest, Essex hunted down mutants, offering them as sacrifices. Sinister was stopped and imprisoned by the X-Men the first time around. However, the next time that Essex faced off against the X-Men, it would be in the form of Apocalypse.

4 TRIED TO CURE THE LEGACY VIRUS

It may come as a surprise to some fans that Sinister actually did a decent thing and desperately searched for a cure for the Legacy Virus, a plague targeting the mutant population. Of course, we should add that Sinister was responsible for releasing it in the first place, albeit accidentally. Needing the mutant populating for his research, Sinister did everything he could to discover a cure.

Moira MacTaggert ended up beating him to it, but not without the cost of Colossus's life. In response, Sinister appeared to extend an olive branch to the X-Men by offering to clone Colossus. But given Sinister's track record, he likely had an ulterior motive.

3 CITY OF CLONES

As if one Mister Sinister weren't enough, Essex created countless clones of himself. Sinister triumphantly claimed that he'd finally created a race superior to mutantkind when he revealed his army of clones in Uncanny X-Men (Vol. 2) #1. Sinister and his multitude of clones took over a part of San Francisco, leading to a conflict with the X-Men.

The X-Men didn't know what they were in for until Hope Summers shot Sinister, only for a different Sinister to take the leadership role. Sinister's consciousness pervaded all of his clones, creating a hive mind and the conflict ended with Sinister and his clones going underground, so that he could continue his research.

2 DNA TAMPERED WITH XAVIER'S DNA

Always thinking ahead, Sinister had a contingency plan regarding the inevitable collapse of his body. Should he pass away, Sinister planned to relocate his consciousness to Professor X, Sebastian Shaw, or Juggernaut. It turns out that he'd prepared them for the transfer early in their childhood, having acquired samples of their DNA.

Sinister perishes in New X-Men (Vol. 2) #46 after Mystique betrays him, allowing for the transferral process to begin. However, after briefly possessing Xavier's body, Sinister's plan is foiled as Shaw and Gambit destroy the device. Sinister had another backup plan though, and it wasn't long before he found another body.

1 TRANSFERS HIS CONSCIOUSNESS

In case the Cronus Device failed -- the machine that would transfer Sinister's consciousness int Professor X -- Sinister's consciousness would then go to a woman by the name of Claudine Renko. In Renko's body, Essex goes by Miss Sinister and continues his activities without missing a step.

Soon, Sinister takes on X-23 and Gambit, which culminates in Renko's body failing Sinister. Again, Sinister transfers his consciousness, this time to a clone of a young girl named Alice. As Alice, he sets into motion his master plan to create an army of his clones, achieving his dream of creating a race superior to Homo Superior.