Alter Ego: Nathaniel Essex Home Town: Keystone City Height: 6'3" Weight: 225 lbs Eyes: Red Hair: Black

Known Powers:
Invulnerability: Mr. Sinister can control the flow of his body molecules in such extend that he suffers -1 CS damage in addition to body armor of Rm rank.

Regeneration: 
Recovery: Un
Telepathy: Un
-force bolts of Un intensity.
-force shields of Un intensity.
-Mental Blocks: the victim must make an Un Psyche FEAT to be able to harm Mr. Sinister. This power takes a year of preparation of the subject.
-Erase/create memories: Un ability, uninterrupted concentration 
-Astral Travel: Sinister has +2CS in astral space.
Morphing: 
-limited shape change: human form, Mn ability.

Equipment:
Base: Sinister can mentally control every aspect of his base
and form restrains or weapons with Mn ability.
Mutant Detection Device: Un

Talents:
Medicine, Engineering, Psychiatry, Bio-Chemistry,
Genetics, Cloning, Computers, Electronics, Resist Domination,
Leadership

Story:
Nathaniel Essex, the man known to become Mr. Sinister was born in Victorian England, there he became a devoted scientist. After his new-born child died he became obsessed with bringing him back to life alienation everyone surrounding him by the unorthodox and 'evil' means with which he was perusing his path. Then Apocalypse crossed his path and awakened Essex's potential to become one of the first mutants and a geneticist in the employment op Apocalypse. What happened after that isn't known, only that Cyclops and Phoenix, send back in time, managed to stop Apocalypse.
It is known that Mr. Sinister had already built an advanced base under an orphanage in Omaha, by the time that Scott Summer's (Cyclops) parents were kidnapped by the alien Shi'ar. Cyclops used his powers to save his brother and himself from a fall from an airplane, when their parents were taken. Sinister's sensors detected the use of the mutant power and Sinister located them.

Sinister had them both transferred to his orphanage, but he allowed Alex to be adopted by foster parents. Sinister wanted to keep Scott and put him under his control. Sinister tried to mentally put blocks on Scott's powers, while at the same time never letting Scott consciously known he existed. A stubborn Scott resisted Sinister, until Sinister was forced to create Scott's ruby quartz glasses, so that Scott could control his powers.

Luckily, Professor X got Scott away from the orphanage and trained him to be the leader of the X-Men. Over the years Sinister kept close watch on Scott and the X-Men, and even somehow gained a tissue sample from Jean Gray (Marvel Girl). He used the tissue sample to create a clone of Jean Gray. The clone would later become imbued with a portion of the Phoenix Force. Sinister would give the clone a set of false memories, and the name of Madelyne Pryor.

Sinister arranged for Scott and the clone to meet, hoping they would fall in love. Sinister knew that any offspring from their union would produce a powerful mutant that he wanted in his power. Things went as Sinister planned, and soon Madelyne and Scott had a son.

Meanwhile, Sinister sent his Marauders on a mutant killing spree. The Marauders attacked the Morlocks who lived in the sewers of New York City. This bought the Marauders into conflict with the X-Men, which ended in a stalemate. During the battle, the Marauders mentioned Mister Sinister, but that is all the X-Men would learn about him for a long time.

Scott left Madelyne to go to the newly resurrected Jean Gray at about the same time that Sinister decided to take Scott and Madelyne's son. Sinister's Marauders got the baby, but Madelyne escaped.

When the events known as the Inferno began, Madelyne, who had now become the Goblin Queen, took her baby from Sinister's base and easily defeated Sinister. During the battle she learned of Sinister's plans and her real origin. The bitter Madelyne swore to destroy the baby, thus ending Sinister's plans.

During her final battle with Jean Gray, Madelyne mentally informed Jean about Sinister and Madelyne's real origin. After the battle, and Madelyne's death, the X-Men and X-Factor swore to get Sinister. Before they could do anything, Sinister mentally attacked Jean. Psylocke, using her mental powers, transported the astral bodies of herself, Wolverine, Storm and Cyclops into Jean's mind. There they discovered Sinister destroying Madelyne's memories, which Jean had absorbed before Madelyne died. Wolverine and Storm convinced the last remnants of Madelyne's personality to fight back, which drove Sinister out of Jean's mind.

Jean, while Sinister was in her mind, learned that he was waiting for them at Professor X's Mansion. The heroes were attacked by members of the Marauders when they got there, and defeated them. While questioning Polaris, who had been possessed by the entity known as Malice, the Mansion exploded. The explosion knocked out all the X-Men, but Polaris stayed conscious. Sinister arrived and ordered her to kill all the X-Men but Jean Grey. Polaris and Sinister were stopped by the late arrival of Longshot and the Beast. Slowly, the other members of the X-Men and X-Factor woke up and attacked. Unfortunately, Sinister and Polaris seemed to be able to counter the heroes' every move.

During the battle, Sinister easily, placed Scott under his control and told him about the real life Scott had in the orphanage. The desperate heroes realized that Sinister might be vulnerable to Scott's force beams, since he had made sure of putting Scott out of commission first. While the others attacked, Scott's brother, Alex, tried to make Scott mad enough to break free of Sinister's control. At the same time, Alex was releasing his plasma bolts at Scott, which increase the power of Scott's force beams.

Suddenly, Sinister got possession of Jean and kissed her. The mere sight of this broke Sinister's control, allowing Scott to fire his beams at Sinister. Beast snatched Jean away before the amplified force beams reached Sinister. The beams hit Sinister dead on and totally destroyed his physical body. But Sinister was not as easily destroyed and later returned to do conflict with the newly formed X-factor and even later he was one of the players in the conflict know as the X-Cutioner's Song.

Sinister might have attracted the Legacy Virus and is looking for a cure. it was also revealed that Gambit might have been one of Sinister's marauders.