Demons are malevolent/evil spirits or creatures often associated with or known as fallen angels, especially in Abrahamic religions. However, in fiction, demons can be a number of malevolent beings normally possessing supernatural influences over different realms and dimensions putting them above your average monsters. They often corrupt, possess, brainwash or destroy the innocence of others.

IMPORTANT NOTES:

• Demons often originate from realms that are evil in nature. This means most only know how to be evil and cannot understand or comprehend what is right and wrong, thus they are mostly chaotic in nature.
  • Beings that become Agents of Hell or similar realms and higher powers are meant to be Damned Souls even if they gain demonic abilities or otherwise (i.e. Scorpion, Alastor, Muzan Kibutsuji, Bathsheba Sherman, Malefor, Griffith, Freddy Krueger, Sephiroth, and Count Dracula).
  • Deities and Cosmic Entities are not necessarily Demons unless they came from something evil (e.g. Dharkon and Scarlet King).
  • Also, DO NOT add certain Fallen Angels to this category who still retain their grace despite their fallen status (e.g. Inarius, Khan Maykr, Cletus, Collin, and Keenie, Gabriel, and Michael).
  • However, Demons can qualify as Pure Evil if they show a clear moral agency and their goals are incredibly twisted, which can also fall under Sadists, especially if they take pleasure of harming and torturing their victims in gruesome ways (e.g. Art the Clown, The Lich, Mephiles the Dark, Valak, Judge Holden, Aku and The Ink Demon).
• This category is for defined demons instead of literal demons. Even if some creatures are called demons in their respective work, if they are not beings originated from evil realms, they don't fall into this category (e.g. Demons (Demon Slayer)), these should go under Damned Souls category instead.