Transformed by Apocalypse into a shape-shifting psionic, Nathaniel Essex was a master manipulator and geneticist, consumed by his search for the ultimate mutant bloodline. Mr. Sinister had transformed Anna Marie into Famine, one of the Horsemen of Apocalypse, along with Pestilence (Beast), War (X-23), and Death (Iceman).
Known Powers: Following genetic alteration by Apocalypse, Sinister possesses a wide array of powers. Over the years, Sinister has used the genetic material of other mutants to grant himself a vast array of powers.
Cellular Shapeshifting: ability to control every molecule of his body, allowing him to assume the form of any one he wishes. He once reduced himself into a semi-liquid state. Enabled via Implanted X-gene taken from the biomolecular metamorph Courier.
- Regenerative Healing Factor: Mister Sinister is able to rapidly regenerate damaged or destroyed tissue with much greater speed and efficiency than an ordinary human. Sinister can fully heal from injuries that result in massive tissue damage or loss such as multiple gunshot wounds, slashes, puncture wounds, broken bones, and severe burns within a matter of moments. It is unknown if he can regenerate missing limbs, but his healing factor has been compared to that of Wolverine.
Superhuman Stamina: Mister Sinister's muscles produce considerably less fatigue toxins than the muscles of ordinary humans. He can exert himself at peak capacity several hours before fatigue begins to affect him.
Superhuman Strength possesses superhuman strength, which may be a product of his shapeshifting. Sinister is able to press lift within 2 to 10 ton range.
Superhuman Reflexes: Mister Sinister's reflexes are enhanced to levels that are beyond the human body's natural limits.
Telepathy: He can read minds and project his own thoughts into the minds of others within a radius of 250 miles (on Earth). With extreme effort he can greatly extend that radius.
- Mental Paralysis: ability to induce temporary mental or physical paralysis
- Mind Control: capable of controlling the minds of others but only one at a time and if the target is in his physical presence.
- Dilate Power: ability to mentally paralyze a foe he's touching and the ability to psionically "turn off" the superpowers of any mutant.
Telekinesis: possesses telekinetic abilities enabling him to levitate and manipulate living beings, inanimate objects, and to some extent energy, psionically. He can “lift” as much as 10 tons of weight and possibly even more and can achieve other effects.
- Concussive Blasts: can fire blasts of concussive force from his hands or from the diamond-shaped scarlet mark on his forehead.
- Force Fields: can erect a force barrier to repel and defend against incoming onslaughts, they're potent enough to stand against Cyclops's optic blasts.
- Flight: Sinister has shown he can use his TK on himself to accommodate flight, how fast is undetermined but it's speed is still impressive nonetheless.
Genius-Level Intellect: Sinister is a genius with expertise in various fields of science, mainly genetics, mutations, human and alien biology, cloning, all levels of physics, engineering (including mechanical, electrical and aerospace engineering) and more. His intellect has been said to match Reed Richards and Doctor Doom and he is one of the smartest people on Earth.
Genius-Level Geneticist: Sinister is a genius and a geneticist of the highest order, able to predict genetic mutations and splice DNA. It is quite probable his powers are the result of self-experimentation - his shapeshifitng power is due to a procedure he performed on himself with help from a time-traveling Gambit. He can also produce large amounts of clones; he has done so with all his Marauders, and with Jean Grey. He is normally described as the world´s greatest geneticist.
Master Surgeon: He is a master surgeon, having excised a portion of Gambit's brain, only to later restore it (although from Sinister's point of view, he restored a portion of Gambit's brain and later excised it, as Gambit was traveling back in time when the restoration was completed; possibly a predestination paradox). Besides this area he is also a skilled doctor.
Skilled Mechanical Engineer: having created devices that seem to have been taken from the tales of Jules Verne. His inventions include advance ships, devices that negate all mutant powers except for his own and many more.
Master Manipulator: He possesses a good deal of knowledge in psychology, and is a skilled manipulator, being able to conceive others with simple words and facial expressions.
He at one time possessed tissue samples of thousands of people, dating possibly as far back as the 1860s, including several American Presidents.
Many of his bases seem to have some quasi-biological properties, able to "grow" tentacles from a surface to hold a prisoner at Sinister's mental commands.
Sinister augments much of his technology with clones of mutants, primarily from the X-Men and Marauders, such as a device harnessing Dazzler's ability to turn sound into light in order to render people mute, or a gun firing the cloned eyeballs of Cyclops as explosives.
He was believed to possess the power of teleportation, but it was revealed this was not an innate ability, but a function of his tesseract headquarters.
- Personality: Sinister is a ruthless man who has no compunctions about ruining the lives of others to get what he wants. He prefers to operate in the shadows, letting lackeys and unsuspecting dupes do his dirty work. He is arrogant, confident, and expects total obedience from his underlings. He is known to have collaborated with members of the Nazi party.