Height: 6'1
Weight: aproxamently 200lbs
Group Affiliation: none, former
pawn of Apocalypse , master
of the Marauders , creator of
Madelyne Pryor
Base of Opperations: none
Powers: Sinister has exhibited a
wide range of abilities and levels of
power, and it remains unclear which
abilities have been induced by the
villain Apocalypse or have been
developed by Sinister himself.
Sinister has increased intellect,
strength, stamina, and reflexes. He
appears able to travel the astral plane
and fire bolts and create shields of
unknown, perhaps psionic, energy.
For some reason, Sinister seemed
vulnerable to the mutant Cyclops'
eye-beams, but whether this was
a ruse remains unclear. Sinister usually
relies on his hi-tech bases with futuristic
weaponry. Theses bases also house
many mutant detecting, monitoring,
and recording devices.
Over the centuries, Essex, soon calling himself Mr. Sinister, plotted the course of certain genetic information. Through unknown means, Sinister built an advanced base beneath an orphanage under his influence in Omaha, Nebraska, called the State Home for Foundlings. When the young child Scott Summer's (later, Cyclops) parents were kidnapped by the alien Shi'ar, Summers used his powers to save his brother and himself from a fall from an airplane. 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.
Eventually, the mutant trainer 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.
When Jean Gray appeared to have died, 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, Nathan.
Meanwhile, Sinister created and/or outfitted several mutant villains for a team called the Marauders. (It has been revealed that the Marauders have been cloned, perhaps extensively, by Sinister and various members once believed dead have reappeared on Sinister's behalf numerous times.) Sinister later sent the Marauders (led by the future X-man Gambit) on a mutant killing spree, targeting the community known as the Morlocks who lived in the sewers of New York City. Sinister wanted a more purified genetic gene pool and believed the Morlocks' existence somehow compromised such a gene pool. The Marauders were confronted by the X-men, which ended in a stalemate.
When Scott left Madelyne to return to the newly resurrected Jean Gray, Sinister decided to take the baby Nathan. Sinister's Marauders got the baby, but Madelyne escaped with the help of the X-men. Nathan was placed in Sinister's base and subjected to experiments. Then, a demon invasion began in New York, and 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 her real origin. After the battle, and Madelyne's death, the X-men swore to get Sinister. Before they could do anything, Sinister mentally attacked Jean. The X-man Psylocke, using her mental powers, transported the astral bodies of herself, Wolverine, Storm and Cyclops into Jean's mind. There they discoviered Sinister psychically 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 Marauder's leader, an 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 Gray. Polaris and Sinister were attacked by the X-men as they revived, and 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. The X-man Beast snatched Jean away before the amplified force beams reached Sinister. The beams hit Sinister dead on and totally destroyed his physical body. In reality, Sinister had not died, (or perhaps had activated a clone.)
More recently, Sinister tricked the High Evolutionary into firing a device that stripped mutants across the world of their powers and caused untold devastation in the community of super-mutants known as the Neo. Sinister was ultimately defeated by the X-Men, and the High Evolutionary reversed the effects of the device. Since then, the Neo have sworn to destroy Sinister at any cost, and Sinister led the Neo to believe they had killed him.