Moon Knight's most gruesome kill is far too violent to ever make it into the Marvel Cinematic Universe. The vigilante once fought his longtime adversary, Bushman, and after defeating him in a rooftop slugfest, Moon Knight did the unthinkable and used one of his crescent darts to carve the face off his opponent and held up the remaining skin like some kind of trophy.
Marc Spector is a former mercenary, who was nearly killed by the man who hired him, Raoul Bushman, on a mission to steal treasure from an Egyptian tomb. Spector was resurrected by the spirit of the Egyptian god of the moon, Knonshu, and was given superpowers, leading him to become the hero, Moon Knight. While he used his moon-based powers to fight crime, Spector struggled with dissociative identity disorder, as he adopted multiple personalities when he was fighting crime. He created multiple identities for himself, including millionaire Steve Grant, a taxi driver named Jake Lockley - both of whom gave him valuable intel when fighting crime.
In Moon Knight #2 (2006) by Charlie Huston, David Finch, Danny Miki, Frank D'Armata, and VC's Joe Caramgna, an injured Spector sits in an empty room, recalling the events of what just happened to him. In a flashback, Moon Knight and Bushman engage in a violent fight. They exchange blows before Moon Knight falls off a rooftop and lands on his back. As Bushman pulls out a sharp blade, the vigilante grabs one of his crescent darts and throws it like a boomerang, which ends up in the back of the villain. As both are on the ground, Moon Knight grabs his face and carves it off with his weapon.
The panel is too gruesome to share here, but Moon Knight holds the skin on Bushman's face as he calls to Khonshu, asking him "is this enough?" With Disney+'s upcoming Oscar Isaac-starring Moon Knight MCU series being PG-13, there's little chance they could ever pull off something as violent as Spector carving the face off of Bushman.
Despite the PG-13 rating, Moon Knight still looks to be an action-packed series that will do justice for the character. Isaac seems to be the perfect fit to play Spector and has shared some impressive training videos showing exciting fight choreography coming to the series. Bushman's death in the comics in this case is too gruesome to ever appear in the Marvel Cinematic Universe, but that doesn't mean the series can't be a violent, dark story of the rise of Moon Knight.