Apocalypse: En Sabah Nur is an Ancient Egyptian shapeshifter with a Social Darwinist streak, Apocalypse is one of the oldest, and one of the most evil ,mutants in existence. Believing that the strong must dominate the weak, Apocalypse aims to test humanity. Those who survive the process will be allowed to live as his servants, those who fail, die. Apocalypse has a history of granting powers to other unscrupulous individuals, transforming Nathaniel Essex into the mad genetecist Mister Sinister (in exchange for Sinister agreeing to unleash a plague that would exterminate most of humanity), and empowering terrorist leader Moses Magnum, in exchange for the latter winnowing out the strong from the weak. His other crimes include, infecting the infant Cable with a technorganic virus, turning Cable's clone, Stryfe, into the monster he is today, trying to force humanity to reduce its own population by ninety percent or face the wrath of another metaplague, and effectively killilng Stryfe by bodyjacking him. That's without getting into the Bad Future, where he rules most of the world and has effectively run it into the ground, or the Age of Apocalypse timeline, where he devastated North America with nuclear weapons, reduced the human population in purges, and gave free reign to likeminded psychopaths Sinister, Holocaust, and Mikhail Rasputin, effectively destroying civilisation. Believing wholeheartedly that those he conisders weak must be slain, Apocalypse is well-deserving of his name.
Selene: Sometime Black Queen of the Hellfire Club, she is one of the few mutants to be older than Apocalypse, and one of the few who can match his evil. A psychic vampire, Selene survives by draining the minds of other beings into herself, a move which brainwashes those she only preys on a little, and kills those she drains completely. She's also possessed of a phenomenal god complex, and has repeatedly tried to attain godhood, and has forced others to worship her. Her crimes include trying to psychically devour the entire city of Rome, using mind control to force the citizens of Nova Roma to worship her as a goddess, trying to kill her own descendant, Magma, successfully killing her loyal servant Eli Bard, manipulating Wither, an otherwise good kid, into descending into omnicidal mania while pretending to love him, promising the Upstarts prizes if they committed enough murders, repeatedly trying to bodyjack Rachel Summers, and enslaving the souls of all Genosha's dead. A seemingly immortal parasite, Selene set the standard for all future Queens of the Hellfire Club to follow.
Fabian Cortez: He was part of the defunct Upstarts, a group of rich, bored dilettante mutants that hunted and killed other mutants for points and bragging rights (the competition was set up by Selene to test possible recruits for the Hellfire Club). In his first outing, he puts together the Acolytes and seeks out Magneto in order to sway him back towards taking an antagonistic stance against humanity again. When Magneto is wounded, Cortez uses his own powers to seemingly heal him and boost his power at the same time whilst making Mags dependent on the “treatments” like a drug (and possibly making Mags more emotionally unstable, which would account for much of his behavior during “Fatal Attractions”). His machinations lead to the U.S. and Russia destroying Asteroid M with a plasma cannon, and the deaths of his entire first group of Acolytes (what makes that worse is that one of them was his own damn sister, and yet he never acknowledges that, nor does he show any signs of remorse or grief), whilst he flees with a triumphant smile on his face. When Magneto turns out not to be dead and he loses his top spot in the Upstarts competition, his response is to go to Genosha and inspire the mutants there to rise up against their oppressive human government, causing a bloody civil war. At the same time, he kidnaps Magneto’s infant granddaughter (and replaces her with a shapeshifting mutant suicide bomber in an attempt to kill as many of the Avengers as possible) so he can use her as a Human Shield against her parents and grandfather, the X-Men, the Avengers, and Exodus. When Magneto is given rule of Genosha, he grants Cortez a place on his cabinet in exchange for regular rejuvenating treatments (Magneto’s powers are in decline at this time). As soon as Mags learns of hidden technology in Genosha that can restore his power levels again, Cortez predictably betrays him again by amping up ex-Acolytes to send against him. Not only an extreme mutant supremacist, a terrorist, a coward, a user, and a backstabber, Cortez also committed his most despicable crimes to score points in a competition.
Mister Sinister: Nathaniel Essex is a nineteenth century eugenicist who believed that people should be bred in order to produce superhumans, Essex was approached by Apocalypse, who granted him near-immortality, regenerative, and psionic powers. Betraying Apocalypse, Sinister struck out on his own. Recognizing his own genetic handiwork in some of the Morloks, a group of street-dwelling mutants, Sinister hired the Marauders to exterminate them, because he viewed their existence as plagiarism. Obsessed with Scott Summers' bloodline, Sinister cloned Jean Grey, and sent the clone, Madelyne Pryor, to have a child with Scott, so that he might then steal the child. He later tried to use the High Evolutionary space station in order to alter the genetics of the entire planet; failing in this endeavor, Sinister later sent out the Marauders to murder everyone who knew about the dark future where Apocalypse ruled the world. On another occasion he merged with the Dreaming Celestial and transformed the entire population of San Francisco into clones of himself. At another time, Sinister, then part of the Weapon X project, promised to free the project's prisoners from the concentration camp they were held in, only to turn around and use them as part of his own experiments. Concerned only with his mad genetic theories, Sinister has worked with everyone from Mengele to Apocalypse in the interest of furthering his research, and making himself the dominant life form on Earth.
Omega Red: Arkady Gregorivich Rossovich was a Soviet soldier stationed at a small town who started murdering from sheer boredom. His fellow soldiers shot him in the back of the head when they caught him. The Russian government learned he survived and recommended him for the Soviet supersoldier project, which he apparently only survived due to his evil and mean nature. To survive carbonadium poisoning, he drains the life forces of those around him, even when a cure is available. It was at one point implied that he was a pedophile, though thankfully, writers seem to have forgotten it (Red was, by this point, developing into too dark a figure). He later turned on and killed several of his employers working for the Hand for the reason that they irritated him. In his presently final issue, he ends up in a regular Russian prison and taunts a prisoner dying of HIV/AIDS by calling him worthless. He later casually kills Wildchild by impaling him through the chest and dumping him in molten lava.
Donald Pierce: The cyborg leader of the Reavers, he was a member of the Hellfire Club for a time, but is really a psychotic, raving bigot who's also a serial killer of mutants. His hatred motivated him to turn people into Cyborgs to kill more mutants. What makes Pierce the worst, though? Pierce knows if he goes after guys like Wolverine, Cyclops, Magneto, or Havok, he's going to get his ass kicked...so he targets baby and child mutants who can't fight back like they can. Pierce is a vile, spiteful, cowardly bully so filled with hate, his last words before Cyclops kills him is to say he's just sorry he won't be around to see the Mutant Race destroyed. The one time he went after Wolverine it was with the help of Lady Deathstrike and the Reavers; they ambushed Wolverine, beat him down, then crucified him in the Australian desert and tortured him. If not for Jubilee, Logan would surely have died; as it was, the ordeal severely taxed his healing factor and screwed up his mental state for months of Comic Book Time (but years of our time). Pierce can actually claim to be among those who have come closest to killing Wolverine, and in such a horrific way that the son of a bitch belongs on this list.
Sabertooth: While Wolverine rejects the savage, animal side of him, another mutant embraces it. Victor Creed has reveled in his savagery ever since he was a boy, when his original origin story was that he killed and ate his parents. Sabretooth became a mercenary after, though he commits multiple murders for his own pleasure as well as profit. Sabretooth is known for making a game of hunting down women and children before killing and eating them. One issue of Deadpool revealed that, after slaughtering a large group of people, he had a little girl locked in his closet as a snack for later. Sabretooth once joined X-Factor, though he was revealed to be faking a Heel-Face Turn to ensure a psychic dependence on an addiction was removed and promptly attempted to murder those he could. Most recently, Sabretooth found himself as an unlikely father figure to Wolverine's amoral son Daken. The reason? Sabretooth played off Daken's desire for fatherly affection and drove him towarda confrontation with his father solely to hurt Wolverine more after he was forced to kill Daken. Every affection he ever had for Daken was a lie: Sabretooth would have killed Daken himself, but wanted the death to be at Wolverine's hands for maximum agony. For decades, Sabretooth has reveled in his monstrosity. He mixes his sadism with a brutal cunning and intellect, and is revealed to remember every life he's ever ended because he savours every death he deals.
Shadow King: Amahl Farouk was a powerful mutant who made his living as a crime lord, using children as pickpockets or prostitutes. After being defeated by Charles Xavier and locked in the astral plane, he became far worse. Taking the alias "The Shadow King," Farouk became a being of psychic malice. Not content to remain on the astral plane, Farouk consistently possesses others with psychic energy, and then enacts a game of destroying them mentally. He often forces them to indulge in the sickest desires he can imagine, or that he finds in their subconscious, leaving them awareness to see that they are doing such horrible things, but that they even enjoy it. Farouk enjoys psychic torture as a hobby, and seeks to corrupt the hearts and minds of every human he can, with Mind Rape being both an art and enjoyable past time to him. Recently, Farouk was the one to reveal to the young boy who might grow to be Apocalypse that his life was a lie and he was the destined destroyer. Being Farouk, he mocked him the entire time about how his life was a worthless simulation, and showed utter glee in awakening the one to commit genocide on humanity.
Reverend William Stryker is the founder of the Purifiers, an organization of religious fanatics who believe mutants are an affront to God. Their first appearance opens with them gunning down a nine year old girl and eleven year old boy. Stryker's crusade began when he killed his baby mutant son...and then broke his wife's neck for giving birth to a "monster." He tries to brainwash Professor Xavier so he'll kill every mutant on the planet and murders his second-in-command when it becomes clear she has the mutant gene. His own guards even turn on him when he tries to kill Kitty Pryde on live TV.
The Founder is the Big Bad of Jason Aaron's run. In the 1920s, The Founder was the young son of a notorious robber-baron whose workers went on strike. The father brought in thugs from the Pinkertons to control the strike, killing many workers. The workers hired Wolverine to fight the thugs. In response to this, the robber-baron murdered the head of the union. In responser to that, Wolverine killed the robber-baron, whose son swore revenge and dedicated the rest of his life to learning everything, everything about Wolverine. Over the years he recruited many others with perceived or real grievances against Logan, forming the cult called the Red Right Hand. When a member tried to leave the group, he forced her to smother to death a helpless old woman (Sabretooth's mother, as it turns out). In the modern day the Founder, now an old man, decided to act against Wolverine personally. He and the other members sold their souls to the hell-lord Marduk Kurios, in return for damning Wolverine to Hell and allowing a demon to possess his body. They then let the demon and their bodyguards, the Mongrels, loose on anyone who had ever been kind to Logan, ever (killing John Wraith, Silver Samurai, and temporarily, Mystique). Once Wolverine got out of Hell and back into his body, he chased after the Founder and the Red Right Hand, killing the Mongrels along the way, only to find that the cult had already committed suicide. The Founder left a tape-recorded confession for Wolverine, though, in which he revealed that he never intended Wolverine to die, oh no. He wanted him to win. Why? Because the Mongrels were Wolverine’s long-forgotten illegitimate children. Even though Wolverine defeated his enemies, the bad guy decidedly won. In the narration for his flashback (provided by him), he mentioned how much he enjoyed what an evil man his father was. To him, the ability to brutalize others is a sign that a person is "strong."
Tomi Shishido, the Gorgon, fully lives up to his name by turning people (especially girls) into living statues, which he uses for decoration. His villainous career started very early, when he founded the Dawn of the White Light, a mutant surpremacy group which put even the Brotherhood to shame. At the age of 18, he slaughtered his entire family in order to prove himself worthy of joining the Hand. His by far most heinous act was when he brainwashed Wolverine into a servant of HYDRA and sent him on a brutal killing spree, which caused several dozen innocent deaths, among them the Hornet and Northstar, which haunts Logan to the present day. He also has absolutely no problems with killing children, which he showed when murdering Phobos.
From the Wolverine: The Best There Is limited series comes the enigmatic Mr. Winsor, alias Contagion. Born from a Latverian eugenics program, Winsor's body contained every single disease known to man, which he trained himself to be able to release at will. Killing all the other children born from the program, Winsor struck out on his own, acquiring the services of numerous nearly-immortal individuals as both enforcers and test subjects, whom he would infect over and over again with his diseases in order to make them stronger and more deadly. Winsor used his abused son, deformed from exposure to his father's diseases, as bait to acquire Wolverine for his experiments under pretense of wanting to use his research to cure his son's condition, knowing Logan, as a Friend to All Children, would never refuse the offer. Ultimately, however, he revealed his true motive: in making his diseases stronger and stronger he hoped to engineer one that could kill absolutely anything, which he would then unleash on the world and then the entire universe via a stolen spaceship. When his followers ceased being useful, he subjected then to And I Must Scream to ensure they would not rebel. With evil plans unmatched in scale for an Earth-based villain, Contagion more than makes up for his brief tenure in the comics with his cruelty.
The Ultimate X-Men has Magneto, in a marked change from his usual Noble Demon status. Sometimes he makes Grant Morrison's Magneto look shy. For a start, though Retcon gave him his more familiar background, originally Ultimate Magneto came from a wealthy American family and was never on the receiving end of a genocide or any sort of prejudice, meaning initially he didn't even a Freudian Excuse for his actions and was even more of an arrogant dick note the Retcon is that he was adopted, and did live through a genocide, though probably a more modern one than the Holocaust (that, or he is a liar). No Well-Intentioned ExtremistAnti-Villain as the mainstream one is, this Magneto is an abusive parent who once broke his own son's legs for challenging him; is a true mutant supremacist who believes that mutants should replace humanity rather than merely be protected from them (in fact, he's even implied to have been eating humans at different points); and has, on several occasions, attempted to eradicate the human race and rule over a post-apocalyptic mutant utopia in the aftermath as an extension of this creed. He is savagely ruthless to his enemies and, here, is the one who crippled Charles Xavier, because the latter had started to realize he was insane. He rules the Brotherhood of Mutants like a cult and encourages them to murder as many humans as possible, children included, and has organized several terrorist attacks with high body counts.
Dr. Zander Rice is one of the lead scientists of Weapon X's X-23 project. He has X-23 kept in a padded room except during training sessions or assassination missions, almost kills her with radiation poisoning to trigger her healing factor at the age of seven, and surgically removes her natural claws one at a time, coats them with adamantium, then re-implants them (all of this without anaesthesia) at the same age. He develops a pheromone "trigger" that activates her berserker rage and uses it to get X-23 to kill her martial arts instructor, and leaves her behind on a mission to be killed after he murders the other members of the team so he can claim they were taking fire and had to retreat. After X-23 shows back up alive, Rice then manipulates the head of the X-23 project, who had raised Rice after his father's death, into granting Rice control of the project, at which point Rice then sends X-23 to kill the man, his wife, and son - even though Rice knows the boy is his son, from an affair between Rice and the wife before her marriage (X-23 leaves the child alive). Upon taking over the project, he begins the development of embryos X-24 through X-50, which he intends to sell to the highest bidders, and then taints the one remaining person X-23 cares about, the project scientist who was her surrogate mother, with the trigger pheromone, which causes X-23 to fatally injure the woman - just as she was about to take X-23 and disappear after destroying the project complex. Rice's reasoning for all of this? His father, who worked on the original (Wolverine) Weapon X project was killed by Wolverine when he escaped, and Rice held X-23, who is Logan's genetic double, responsible for Wolverine's killing of his father.
Johnston Coffin, featured in four obscure issues of Generation X, is wanted by S.H.I.E.L.D. for crimes against humanity, but instead somehow finds himself employed by the US Government. With the government's blessing, he builds a Hellhole Prison where he "fixes" disobedient teenagers, many of which had only said or thought something disobedient. What really puts him over the line, though, are his "Special Children" - kids from his first Hellhole Prison in the '70s, whom he's wired up to huge cyborg bodies and uses as security. They've been that way so long, it's implied in perpetual agony, that their bodies have actually begun to rot. He also has half a human mounted on his wall, is implied to be a rapist, and carries around the skull of a child he shot in the head everywhere he goes.