Estranged from his wife Rebecca, Nathaniel at the last moment before her death at childbirth begged her forgiveness for committing such atrocities in his experiments, but found little consolation, as she cursed him, with her last breath calling him - Sinister. Mad with grief, he accepted Apocalypse's offer to rise above humanity, to lose his emotions, so he could find release from the pain of losing his family. As a last reminder of Rebecca and the life he left behind, his humanity, he took the name Rebecca had last called him. Emerging from Apocalypse's machinery, Nathaniel Essex was reborn more than human - or maybe less - as Mr. Sinister! At this critical juncture in time he and Apocalypse, however, were opposed by the temporally displaced Cyclops and Phoenix of the X-Men.

This was his first glimpse and the source of his obsession on the Summers bloodline and Scott and Jean's offspring. He sought out the gene line that would one day produce Scott Summers and awaited his time, all the time perfecting his scientific knowledge from the 19th century, through both World Wars and the better part of this century, waiting for his time to come - the emergence of Homo Superior and the man who would become Cyclops. Initially he cultivated the gene lines of the Marauders, a pack of London-bound cutthroats, as an early practice in his newfound equipment and the power derived thereof. He has refined these people for generations and those of their current descendants that Sinister has deemed worthy of further study and genetic potential, are now serving him in his savage Marauders.

This generation of Marauders is the first to manifest super-powers and Sinister has thus sent them on various missions after discovering this. He keeps the originals in clone chambers at all times and only uses their clones to further his ends. In the 1930's he became involved with a woman named Faye Livingstone, a woman bearing a latent X-factor in her genes that would potentially bring about more powerful offspring than the Summers bloodline. Posing as an aristocrat, Essex seduced Faye and studied her for some time. Soon, though, Faye discovered Essex's true identity and was horrified as Nathaniel revealed his plans to her. She was held and studied for years, humiliated and her will broken, until one night she suddenly, abruptly, was let go. She ran off into the night, with Sinister watching unemotionally as she left his life. Secretly, though, he had in fact fallen in love with Faye and discovered for the first time in his life as Sinister that he did have emotions. Confused and uncomfortable with these feelings, he forced them away then to continue his work in science.

It was only in the recent years that, when he discovered Faye was dying of cancer, and comatose in a hospital, that those feelings came back, after being on the background for so many years. Kidnapped by Genesis, Faye was sought out by Nathaniel, who wanted to finally make amends while it still was possible. The two were mind-linked by Phoenix of the X-Men, and shared their souls, before Faye died. After seeing her die, Sinister once again, just after finally admitting his emotions, pushed them away again - this time further than ever before, hurt even more than by Rebecca's death, because in the end, both women had known what he was, but unlike Rebecca, Faye had still loved him. His dreams finally came true when in the mid-fifties he found out of Scott Summers' birth. He monitored the boy carefully, as well as the entire family, for years in silence.

But when Scott's parents were lost in space and he and his brother Alex taken into an orphanage, Sinister saw that his time had come. He arranged for Scott to be transferred to an orphanage run by him, where he studied the boy intensely for years, placing mental blocks in his mind that Scott has later overcome. In his teens, when his mutant powers first manifested, a pair of ruby quartz lenses were ready for him, having been forged already in the 1860's when that material was created by Apocalypse's equipment to absorb Scott's optic blasts. Sinister had appropriated this material and fabricated the glasses to wait for their rightful owner - the one mutant whose optic blasts would match with the quartz's absorption frequency would be the one he had waited for.

Soon after his powers had manifested, though, Scott escaped the orphanage and joined the X-Men. All this Sinister had carefully arranged, like he had the accident which had killed Jean Grey's best friend, sending her into a catatonic state, so that she would be sent to Charles Xavier to be examined. Steering from the sidelines Sinister arranged for these two people's destinies to entwine - and eventually produce the offspring he had awaited.

When the first wave of mutants - the first true generation to have a significant amount of mutants - surfaced in the 1960's, Sinister knew that his time had come. While Charles Xavier founded his X-Men, so did Sinister scour the world for his team of mutants. They were of their own volition dubbed the "Nasty Boys" and were trained for more subtle and less savage work than the Marauders would be. Sinister spent a lot of time during the next decade studying these people and others of the first generation.

For the first time he was overworked, and couldn't study all the mutants he could find. The situation was made even better - a true banquet of genetic courses - when the second generation arose after the mid-70's. He now limited himself to only superficially examining most mutants from afar and concentrating his efforts on the most promising ones. Now both members of the X-Men, Scott Summers and Jean Grey soon fell in love and Sinister eagerly awaited their offspring. Sinister watched their relationship grow over time, but when Jean supposedly became the Phoenix, Sinister anticipated the final outcome - that Jean would be corrupted and destroyed by the power - and quickly got to work on a contingency plan. He acquired genetic samples of Jean Grey and cloned her.

But the Phoenix was subconsciously keeping Jean telepathically sedated in her cocoon in Jamaica Bay. It also mistook the clone for Jean, and confused, kept them both comatose. When the Phoenix died, the piece of Jean's soul it had borrowed returned to Jean. But she rejected it, and instead, the soul fragment went to the clone who accepted it and now was no longer comatose. Sinister saw the clone rise and dubbed her Madelyne Pryor, and now telepathically gave her memories of a "prior" life and put in a subconscious urge to seek out and marry Scott Summers, and to have children with him. This plan worked and Sinister finally saw the child he had waited for over a century. He was almost in his grasp, but he waited for an opportune moment to strike. When Scott left Maddie for X-Factor, Sinister saw that his time had come.

Now, he sent his new generation of Marauders to wipe out the Morlocks, a clan of mutants that was to him, an abomination and a waste of the mutant gene pool. He recruited the Cajun mutant Gambit to lead the Marauders to the Morlocks, and in the process studied Gambit and his genetic heritage, discovering that he is of the Summers genestock - a half-brother of Scott and Alex from their father's side. With the assault on the Morlock sewers, he also produced a feint, drawing all the X-people to that "Mutant Massacre", leaving Maddie and the baby open. Sinister kidnapped both, and eliminated any evidence to their existence, but Maddie managed to escape and joined up with the X-Men. Sinister also manipulated Malice to possess Polaris, so that Lorna's genes would be available to him. He sent the Marauders up against the X-Men, in attempt to eliminate the ones opposing him, but they consistently failed. Sinister also now coveted Jean, after learning that she was alive - and fought the X-Men and X-Factor over her, but lost.

Also, X-Factor retrieved Scott's child from Sinister. After his loss, Sinister has learned from his failure and now stays more in the background. He has killed a person who would have caused the deaths of Alex Summers and Lorna Dane. He has no interest in Cable, because he has been tainted with the T-O virus and cannot access his full potential, but is intrigued by the appearance of the untainted Cable, X-Man. Also, he has been monitoring Gambit and his relationship with Rogue. Very recently he has learned of two more Summers siblings, Adam and Trisha, who have come to Earth from the Shi'Ar empire.

He will manipulate others, even people he cares for, to meet his own ends. He trusts no one, but is a master of illusion when it comes to social things. One of his favorite things in the world is get people who hate him and what he stands for into his debt; sometimes, he'll go to great lengths to help his foes, just to have them owe him. With respect to his minions, on the other hand, Sinister will brook no challenges to his authority; rebelliousness will be crushed, immediately and completely. Sinister is a talker and deal maker. He's a silver-tongued devil who has a nasty habit of offering just what you need...at a price. Sinister is absolutely convinced that he is going to win out in the long run, and behaves accordingly. Even he is aware of this supreme self-confidence, and wonders whether it may be his fatal flaw; on the other hand, he reasons, he's won all his battles so far, and there's no reason to expect his luck to change.

Sinister is driven by his desire to create perfection for the sake of art and science. He follows his visions of the future like a religion, and it blinds him to the pain and sorrow he creates for others in his so doing. He might even acknowledge that he does cause pain, but it matters little most of the time, compared to the regard he holds for his designs. That almost always outweighs any other consideration. He shows careful attention to detail and hardly does anything without care as to every angle of its merit. This carries over to even smaller things though to a somewhat lesser degree.

Sinister is a plotter and schemer--and if he aspires to take over the world, he'll do it by stealth and guile rather than brute force. Sinister prefers to undermine from within than to smash from without. He is careful in studying his opponents weaknesses (as well as his minions) and exploiting them to the fullest. His favorite such weakness to exploit is a sense of morality and heroism; it gives him no end of amusement to put so-called heroes in no-win situations. Sinister is a modern fellow, who despite his great age, learned long ago that one had to change with the times. He goes by "Mister" to emphasize his willingness to negotiate and make deals with just about anyone.

He is patient, when watching one of his plans unfold, but also excited by each stage. He sees successes as inevitable and setbacks as chances to raise the stakes. When he wins, he is delighted, and when he loses, he's amused -- secure in the unshakable conviction that he'll win anyway, in due time. His confidence in himself is so great that, upon occasion, he'll give up a victory if it has been too easily won--certain that he can win when he puts his mind to it, but also wanting to prolong the game.

Because he is not truthful with himself about his true feelings, he has a vulnerable heart. Though he might hide it expertly, he is troubled by his lost loves and the loss of his first boy, Adam. He would put his work and his children before his own safety.

Sinister is an extremely powerful telepath and while weaker than Xavier or the Shadow King, he would rank only just below them and perhaps level with Emma Frost. His most limiting factor is his telepathic range, which is only some 3 miles. Sinister is capable of directing a focused blast of psionic energy that can completely destroy an unshielded mind, rendering it incapable of thought, memory or cohesion. He has precise control over this ability and is able to regulate the force of the bolt to stun or render unconscious, or simply daze and confuse, or artfully create pain. The more protected a mind is and the less distance between his ability and someone's shields, the less overall damage he can do.

He can construct psionic defensive barriers about his own mind or others, up to 20 at one time. At its strongest, such as when he shields only himself, his mind is impenetrable to all. Only Xavier with his Cerebro device could penetrate Sinister's psyche. He can forge and maintain mind links, managing up to 20 distinct links at a time, keeping track of individuals across the planet.

He is capable of subtly or forcefully dominating individuals and have them do what ever he would have them to. The amount of time needed to penetrate someone's psi-shields depends on how strong the shields are and how delicately and unnoticed he wants to enter the mind. Given no shields, he can enter immediately, undetected. Given meager shields, he can enter over the course of minutes, undetected. Given a trained mind with respectable psi-shields, like Jean Grey or Psylocke, it would take upwards of fifteen minutes.

Sinister can, with the force of his will, directly access the region of the mind which controls someone's mutant powers, shutting them on or off at his will. If he gets a hold of someone while they are young or while they are unconscious, he can place blocks so that they cannot use their powers against him.

Given time he is able to create elaborate mental blocks in the minds of others that are virtually irremovable. It would take a telepath such as Emma or Xavier hours or days to attempt to remove his work as he is by far the most skilled at manipulation this way.. He can plant false or misleading memories with such precision, it would take another telepath of a high rank to undo them and during the interim, the victim will honestly believe that those are his/her real memories, making any redaction all the more difficult. He can erase memories with incredible precision, to the point where they are completely gone and unrestorable. This mental reconstruction can be so pervasive that destruction of the victim's psyche can occur with tampering of blocks.

Sinister is capable of projecting his psyche into the astral plane and is a complete master of astral combat. He is able to be active on this plane for an indefinite period of time if his body is undisturbed, as his body requires no sustenance. He can project into the mind of someone and bring others to this plane. He is capable of reshaping his body into any form he chooses, and capable of effortlessly maintaining its shape indefinitely. He can carry off complex impersonations, mimicking others, gaining or losing mass in the process. He often uses impersonations to further his schemes. He has complete control over every molecule of his body.

His malleable body deforms along impact lines so that Sinister takes little or no damage from physical impacts. He has withstood punches from Rogue, being shot through the head--all without pain or injury. It is unknown how great a physical force is required to injure Mister Sinister. His body can similarly withstand a great deal of energy without sustaining injury, and he has withstood the full force of Havoc's plasma blasts and Storm's lightning combined. Again, it is unknown how great an energy force is required to harm Mister Sinister. His seeming immortality is the result of his body's infinite capacity for regeneration and self-control. He does not need to breath or eat to stay alive. Sinister does not bleed. Sinister rarely engages in feats of strength, but he is immensely strong, perhaps as strong as Colossus.

He is highly vulnerable to Cyclop's eyebeams to the point where they will penetrate his forcefield with easy to strike his corporeality. He suffers real pain from such an attack.

Sinister is capable of mustering up to 10 tons of force with his telekinesis, which can be used to hold peopleimmobile, form a force shield about himself or to use as a tk blast. Sinister is capable of gating back and forth between his tesseract space. He does so by opening doorways to and from the space, and can keep a doorway open indefinitely, allowing as many individuals as he chooses to pass. He is capable of dropping a portal over himself, or someone else.

Sinister's knowledge and understanding of human biology and how to treat disease is superior to almost any other person, mutant, human or alien. He has even expanded beyond what Apocalypse knows of life and medical engineering. He is capable of designing and creating extremely high-tech and complex instruments and weaponry such as the implants he uses to link the minds of his Marauders. He has a very deep understanding of the way a mind works. He is like unto Charles in clinical psychology and therapy levels, he has also studied some parapsychology especially that which involves dimension theory, cosmology and psionic meta-normal abilities.

As above, he is beyond most peoples' comprehension in his understanding of these things, he can keep people in suspended animation for indefinite periods, arrest traumatic injuries and reverse them. He can cause a body to regenerate as well as alter their powers and abilities.

Sinister is one of the world's greatest genetic engineers. He knows more about mutant evolution and genetics than almost anyone. This borders at time on a flaw, since Sinister is obsessed with genetic knowledge and will act irrationally to acquire new technologies or information. Just as significant is eugenics; this is his life work.. and he has had a very long life. He has samples from every notable person he could find from places throughout time and the known worlds. He stores samples, multiple samples in secret places all over the world, and in his tesseract spaces.

He has the resources skill and equipment to clone whole sentient organisms from a few representative cells. He has done it, he can, and he will. He has clones of his henchmen available such any die in his service. He has knowledge and skill enough here to use and build computers with comparable complexity and ability as the X-Men's Shi'ar enhanced equipment. He knows just what hurts, and just how much you can take, and while he does not engage in this for pleasure (much), he must know what is sensitive in order to manipulate them to his will, or protect them from feeling pain while engaging in genetic alterations and nifty body enhancements. His strong and magnetic presence, combined with his manipulative nature and the drive he has for his goals, make him a very good leader. Plus if you don't do what he says, he will hurt you.

He has living, adjustable restraints that can sense and correct for any prisoner the exact amount of force needed to keep a captured victim held. He has force fields that turn the force of the resistance, both kinetic and energy in nature into force against the individual attempting to affect the forcefield.

He has adjustable mutant power inhibitors that can be set full force to dampen any mutant power, and can be adjusted to lesser effects, allowing for various levels of dampening. These exist in the forms of generator fields and cuffs as well as collars. He has within his tesseract, a machine called masterbrain, which is actually an organic computer he uses for remote control of things within the tesseract, and for the running of programs and monitoring his pods and people within. It helps run the auto-doc functions, and helps keep the security of his places. It tells him of things happening within the tesseract, and helps him magnify his already great telepathic powers when the subject is within the tesseract and hooked up to it though one of the pods.

He has the ability to teleport both by using his power, and by means of his teleport devices, which he can make small enough to insert within the sculls of his minions without harming them. He can bring someone from anywhere in the time space continuum to him, and send the person away to any time/space as well. He also has a number of movable portals he has made in the form of puzzle boxes. These boxes open to various places and keep a sustained portal open to the place for as long as the box is open to a certain position. The puzzles are intricate and difficult to discern. Depending on the position of the box, it will open to different places within his tesseract and to his various bases.

Sinister has highly advanced equipment crafted from both inorganic and organic "machinery" which is able to clone, graft, create, heal and completely regenerate bodies from as little as a singe viable cell.

The tesseract is a place created by Sinister using his powers and augmented by his technology that exists outside of normal space and time, and allows him access to any place on earth, and any time. Its numerous rooms contain some of his labs and some of the pods containing and storing various DNA samples. It also contains rooms for detaining prisoners, and for his viewing, much like scrying of the world outside his separate 4th dimensional place, and he is able to affect the world beyond a portal with his telekinesis. His tesseract links the various places that house his bases, and holds much of his technology.

Sinister has an incredibly sophisticated computer and communications center inside the tesseract from where he can track any mutant signature across the planet. This information is recorded for his perusal, and he can have masterbrain notify him of certain on-goings. He also has sophisticated communicators which he can implant inside the skulls of his minions that simulate telepathic communication. He can, of course, monitor and record all this communication.

Sinister has had centuries to amass all the monetary tools he would ever need. He has luxurious palace like dwellings all over the world, and some off world, in other dimensions. Namely, in the tesseract of his own design. Sinister has his headquarters in a fourth-dimensional hyper-cube, a strange extra-spatial phenomenon which allows him access to all points of normal space and time on the earth (and beyond). He can travel into or out of his tesseract at will, appearing and disappearing as if by teleportation. It is here that Sinister has vast amounts of databanks and computers which store genetic information and monitor the world's information conduits. He is apparently in metal rapport with his base, such that it can change shape and move according to his commands. It is formed partially out of his consciousness and linked to this plane by his mental disciplines and by an artifact he created, much like the puzzle boxes of Hellraiser stories. It allows him to peek in on the goings on of his little projects without physically being there unless such places are guarded by magic, or technology that stops such things as teleports. Equipment: He's in constant contact with his base (see above). He also has mutant detection devices that are similar to Cerebro.

Weapons restraints and other devices are readily available, either being formed of this extra dimensional matter, or by things he has grown and designed. His knowledge resources and skill puts him on par with Forge, or the Shi'ar tech that Professor X has at his disposal. Information: Through his equipment in the tesseract he is privy to immense amounts of information, ranking from the mundane to the confidential. Sinister is one of the most well-informed beings on the planet.

Various contacts include members of the Inner Circle to the Hellfire Club, and he has wheedled his way into knowledgeable peoples lives within the government especially those involved with mutant affairs. They are unaware of his true identity, as he has done much of this spying with telepathy and his shapeshifting. Sinister's agenda is a mysterious one. Although he is among Apocalypse's highest ranking officials, Sinister does not believe in Apocalypse's agenda and has his own plans. To aid him, Sinister has adopted both the Summers brothers and put them in charge of security at the pen where genetic experiments for Apocalypse's empire are conducted. Sinister has secretly utilized genetic material from both Cyclops and Jean Grey to create what is potentially the most powerful mutant alive. It has been made clear by Sinister that this weapon was created for no other purpose than to destroy Apocalypse once and for all. . . .