Loki Steinbach, known to most of the world by the nickname The Mad Jackson Killer, is a prolific serial killer who first made an appearance in Somarinoa's horror novel, The Devil's Pacifism. Since then he has become a recurring character throughout a number of the Lunatic Entertainment games (a pseudogame company name used by Somarinoa), and is in effect the company's mascot. Initially simply the alter-ego for the novel's murdering side, he has since evolved into a shadow demon character with control over darkness itself.
When in a corporeal, humanoid form (or when simply Human to begin with), Loki appears as a dark, mysterious figure, often with a sinister leer emblazoned across his face. He has bright green eyes and long, black hair and (usually a) goatee. His bangs are long enough to reach his nipples and he usually keeps these curled back behind his ears and extending down his chest. Somewhat Gothic by nature, he wears all black: A pair of slip-on shoes, slacks, tight-fitting leather gloves, a customized t-shirt with a silver skull in the middle flanked by the words "F**K" and "YOU", spelling out what looks like simply "KO" from underneath his heavy black trenchcoat. Adorning his head is a black top hat as well, fitted with a $20 American dollar bill tucked into the hat brim, leading to his nickname as the "mad Jackson"—a reference to wearing a top hat like Lewis Carroll's character, the Mad Hatter, and Andrew Jackson, the US president who adorns the bill.
Originally born in 1922 in Germany, he would eventually come to serve with his brothers Donar and Paltar under the armies of the Third Reich of Adolf Hitler. All three brothers were stationed as such to take the war to Norway, and they helped occupy it, although all three would be killed in the process. Loki believed in Hitler's regime, and eagerly joined the military when he became 18. He found his brother Paltar's timidness pathetic and a disgrace to their family, while he was not pleased with Donar's complacency but was okay with it. Loki during the course of the war proved to be a sociopathic individual, and had the Third Reich survived (and had he survived, as well) he could have easily become one of Hitler's prime agents.
Loki and his two brothers were all killed at the same time, while attempting to pull a shellshocked Paltar out of the trenches. Sent to Hell for his transgressions after death, he became the "son" of Sataan, a demon baroness. Eventually she ordered the three to return to the surface world, where they emerged into the 21st Century with no memories of their past as Nazi soldiers. Loki had transformed into a shadow demon during his period of existence in Hell, and he kept his sociopathic nature upon his return to Earth, becoming a serial killer. He still doesn't like Paltar (now known as Baldur) very much, although that's not saying much as Loki doesn't like many people to begin with — to him they're all just potential targets. Even so he has several friends, with the most notable being Shazia.
- The Devil's Pacifism: In The Devil's Pacifism, Loki is simply the name taken by Thor Steinbach during his serial killing sprees. This appearance cemented his overall appearance throughout his numerous cameos, as well as a good deal of his personality, although he would lose his disgust over promiscuous females after this novel.
- Mortal Kombat ♃: Loki was retroactively added to Mortal Kombat ♃ after its revitalization. In this appearance he is simply a demon from the NetherRealm with the appearance of a hatted shadow person. He escaped to Earthrealm after Mortal Kombat 3 where he proceeds to murder large numbers of victims for his own pleasure. He is referred to as "The Mad Jackson Killer" by the police force who have no idea that he is truly a demon.
- Dead Flies: In this webcomic produced by Somarinoa, Loki is one of the three brothers. It is here that his background information comes from. This background is only ever referred to in Dead Flies, though it is mentioned only late in the comic's continuity.
- Resident Evil: Caught in the Crossfire: Though Loki himself does not appear in this game, a large swarm of infected ants utilized as one of the game's many bosses take the form of him as they ebb and flow about the battlefield. This boss is referred to as "LOKI".
- Kevin Poacher, MD: Loki appears as a hidden boss in this strange platformer game.
- Silent Hill: Devil's Pacifism: Loki appears as one of the unlockable costumes for Thor Steinbach, the main character, as well as in one of the game's 6 endings. An iteration of him also appears as one of the story's/game's night terrors, known here as Twilit Urge. This terror not only is fought but also makes a sort of easter egg appearance during the battle against Soft Touch and Leg Caress. Defeating Twilit Urge in the game version of the story awards the player the "Down With The Sickness" achievement/trophy.
- Ultimate Showdown: Loki appears as a form of "The Creator" character in this game, able to utilize his various shadow demon abilities. He is much more vulnerable in areas with less shadows in this form.
- Master of Survival: Deliver Every Friday: Loki appears as a boss in one of this games' worlds. In this, he absorbs a huge amount of shadows to transform into a monstrous opponent.
- Alternate Fantasy: Loki appears as one of Vuul'huukos' deities, serving as the evil god of the Darkness element, putting him as the rival to Hadess, Sal'jaedon's chosen deity.
- They Rise: Thor Steinbach, one of the three main characters of this game, can wear a costume resembling Loki, which increases blade weapon damage. With this outfit on however he is considered a Psychopath and cannot rescue the various survivors found throughout the world.
- God Eraser: Loki appears as one of the possible Demon party members within this Turn-Based RPG.
- Troublesome Dicks: Loki appears in this game as one of the three main characters, a private eye who uses a pair of combat knives to fight his opponents in this Point & Click / Turn-Based RPG game.