He seemed to have a fragmented psyche or dissociative identity disorder and had developed at least four distinct personalities; Marc Spector, Steven Grant, Moon Knight and Inner Child a young, but precocious, red-haired little girl, all of whom he would have conversations with inside his mind. He lived with a woman named Marlene who was his girlfriend at the time. She often complained about his different personalities and how she was never sure which one she was dealing with.
Moon Knight attacked Spider-Man when he mistakenly believed he had blown up a nearby building. This battle with Spider-Man put him at grudging odds with the younger hero in future encounters. Later, after videotaping Captain De Wolfe in Chinatown as Steven Grant, he went out as Moon Knight only to engage in the gang war waged by the Kingpin and the newcomer Hammerhead. During his battle with Spider-Man, Iron Fist, and Shang Chi he was impaled with a sai to the chest by the assassin Elektra. Right before falling out into a coma, he impaled Elektra with a moon-blade into the back of her head before she could kill the Black Cat. Once he woke up, Moon Knight escaped from custody and engaged in another fight with the Punisher, Spider-Man, and Daredevil.
After the battle, Daredevil invited Moon Knight to join an organization of super-heroes with the goal of bringing down the Kingpin. As part of Daredevil's team, Spector adopted the identity of Ronin to infiltrate the Kingpin while acting as a double agent.
The Kingpin told Ronin to prove himself by retrieving Spider-Man. Ronin drove a school bus into Midtown High School and started firing a gun to get Spider-Man to fight. Kitty Pryde, who had recently enrolled there as a student, confronted him, but was knocked unconscious shortly before Spider-Man arrived. The two engaged in a brutal battle that was mirrored in a fight between Moon Knight and Ronin in his mind. Ronin knocked Spider-Man unconscious in the end and The Moon Knight personality was seemingly killed. Ronin used Spider-Man's own web-shooters to leave the high school, and took him to the Kingpin, who threatened and gloated about his plans for the hero while he held him in a secret basement level of his building. 
Iron Fist was revealed to have betrayed the team, though only to save his daughter. The Kingpin had learned through him that Ronin was working for Daredevil and kept that knowledge to himself until after Ronin captured Spider-Man. Ronin was then present in the Kingpin's interrogation with an unmasked Spider-Man, and was then brutally beaten by Kingpin alongside Spider-Man. The Kingpin then ordered Ronin's execution. Kingpin's men took Ronin by a river and shot him in the head. However, he regained consciousness thanks to his multiple personalities, and survived along with his Moon Knight personality. He went to the police and told them that the Kingpin attempted to murder him. This provided a big enough charge for the police to arrest the Kingpin as he attempted to flee the country, but Spector had to reveal his secret identity for a charge to be placed. The public hailed him a hero for his efforts.
Powers and Abilities
He is faster than Spider-Man, may have possessed some level of enhanced strength, even before Doctor Strange's mystical enhancements (such as when he broke a brick wall by kicking it in Ultimate Spider-Man #80, and accelerated healing, possibly based around his DID (such as when he woke himself from a coma in Ultimate Spider-Man Annual #2 and when he survived a gunshot wound to the head at point blank range in Ultimate Spider-Man #110, both due to his various personalities telling him to "wake up")
- Moon Knight is an exceptional athlete, acrobat, and combatant, skilled in various weapons and martial arts, capable of shattering brickwork with a blow. He was skilled enough to defeat Spider-Man and Kitty Pryde, who'd been combat-trained by Wolverine, in single combat and kidnap the former with ease. He also had his fingerprints burned off to make it more difficult to identify him.
- Unlike most Dissociative Identity Disorder sufferers, Spector's personae are aware of each other and their actions and are able to facture Spector's mind further to create new personae when necessary and even kill one another to retain control. They usually cooperate to achieve shared goals despite differing viewpoints although they can overpower one another. when Moon Knight has twice been rendered deeply unconscious or comatose by severe injuries, the others remained active in his mindscape and proved capable or reviving him.
As Moon Knight he uses high carbon steel alloy crescent-shaped throwing darts and a battle staff;
A cabinet in Steven Grant's office contained a white baton, a short spear, a sword, an axe and at least five moon-blades.
- It is unknown if he survived Ultimatum.
- He sometimes used the hood in his cape in the same way his Earth-616 counterpart does.
- In Ultimate Spider-Man #110 Spector is referred to as 'Steven Grant AKA Mark Spector' making it possible that his legally recognised original identity is Steven Grant and not Mark Spector.
- 15 appearance(s) of Marc Spector (Earth-1610)
- 1 mention(s) of Marc Spector (Earth-1610)
- 15 image(s) of Marc Spector (Earth-1610)