Demon

Demon (デーモン Dēmon) is a hidden major villain in Lust Friend, Succubus Puttel and Succubus in Wonderland. She only truly appears in the genocide routes of these games, though the player can find mentions of her throughout Lust Friend. The Record Keeper Fairy that appears throughout Lust Friend is actually her sealed form.

Appearance
Demon has pale skin, dark eyes, long white hair, two horns of different colours (black and white), and three pairs of tattered wings. She wears square-framed eyeglasses, a skimpy V-shaped piece of clothing, elbow-length gloves and knee-length boots.

Personality
Little is shown of Demon's personality, due to her limited screentime. However, she describes her purpose as being to destroy the succubus world. She considers the struggles of the succubi who sealed her to be amusing. She also shows herself to be highly manipulative, attempting to convince Magrut to commit genocide on the succubi.

Background
In the past, Demon was a powerful succubus who killed many other succubi and was a threat to the entire succubus world. After many years of struggling, she was defeated thanks to the combined efforts of Empress (the succubus queen) and her friends. However, they were only able to seal her into a weakened form, that of a fairy.

Lust Friend
Demon appears throughout the game in the form of the Record Keeper Fairy. She allows the player to save their progress. Her dialogue changes depending on the number of enemies the player has defeated, with numerous references to death. At one stage, it will by mostly obscured by boxes (■).

Eventually, the Record Keeper Fairy in Magrut's house will offer to give Magrut a special badge which allows him to permanently kill succubi, claiming that this will allow him to return home sooner. If Magrut proceeds to kill all of the other succubi in the world, Demon appears before him as a fairy (now named a "Save Fairy"), congratulates him for "clearing the game" and gives him the option of saving. Demon then reveals her true identity and explains that Magrut's actions have allowed her to break her seal. Additionally, she says that Magrut has fulfilled her goal of destroying the succubus world. She tells the player to close the game window, and can do this herself if the player tries to continue. If the player tries to reopen the game, they will be faced with Demon again, who offers to create a copy of the game world for them to continue playing in.

Trivia

 * Demon appears to be inspired by Chara from the game Undertale, the latter being the inspiration for Lust Friend. Like Chara, Demon only appears if the player commits genocide on the game's enemies. Notably, at one point in Undertale, Chara is described as (emphasis added) "the demon that comes when people call its name".