Demon

A Demon (or Hostile Sub-Terrestrial) was the designation for a number of life-forms separate from the animalia kingdom and generally considered to be evil due to its lack of a human soul and its destructive tendencies. The term is widely used to describe any creature that isn't a god, robot, unmodified human, or standard terrestrial animal. Though individual powers vary between different demon species, most, if not all, demon species possess greater physical strength than humans.

The generally humanoid demons are not true demons, but are, in fact, 'tainted'. True Demons are huge monstrous creatures. These monstrous Demons are vastly powerful, but far from indestructible.

The lesser demons for the most part will tend to be anti-social, aggressive, violent, easily incited to anger and hatred, and generally just kind of mean, nasty folks. While their essential identities would survive the deaths of their bodies, without a 'soul' they have no direct connection to a Higher Power, and as such, their discarnate personalities would either wander around causing random amounts of mischief and harm out of malice and spite, get eaten by psychic predators, get enslaved to provide psychic power to necromancers, or wind up leaving the material dimension of Earth entirely and winding up in some demonic Hell realm where, they'd be tormented and, at best, end up in the service of some more powerful Demon lord there. All of which lead lesser demons with any intelligence and foresight to try to exercise one or both of two available options: either (a) making their physical bodies as close to immortal as possible to avoid the whole afterlife of torment thingie, or (b) making some kind of deal with some sort of greater Demon to enter into their service voluntarily, on this mortal plane and/or in the afterlife, so they would at least know where they're going to end up and what's going to happen there.

The gradual evolution of the soulless prehistorics into many different demon races, and the soulful primates into considerably fewer human races, is attributable to direct genetic and magical manipulation of the demonic races by Greater Demons, as opposed to a relative lack of such manipulation of human genetics by the Higher Powers.

There are lesser demon races here on Earth and Greater Demons dwelling in the Outer Dimensions trying to get back to Earth and all sorts of demons of varying power levels and appearances and abilities in between living in other dimensions but traveling to Earth fairly often when summoned. Because they have at least some necromantic energy in their bodily make up, most lesser demons have adapted, over the generations, and developed the power to shapeshift into a semblance of human shape. Most lesser demons are stronger and tougher than normal humans. Some of the more powerful lesser demons can enter into pacts with Greater Demons for many different things, usually expressed as increased mortal power.

Despite the obvious fact that there are many physical differences between demons and humans (and between demons and demons, for that matter), the primary difference between the two groups is psychic, and defined by the presence or absence of a soul. This is underscored by the fact that demons can be nourished by human flesh, can use human bodies as incubators for their own young, and, especially, can interbreed with humanity in many cases and have fertile offspring.

Human views on demons
Until the 21st century, most humans remained unaware or in denial of the existence of demons. Those who are aware, however, have widely varied opinions on demons, though most are prejudiced against them. Many of the protagonists of both Buffy and Angel were in fact prejudiced against demons for a time.


 * The Watchers' Council refused to help Buffy Summers cure Angel of the Killer of the Dead poison on the grounds that he is a vampire, which resulted in her severing ties with the Council for over a year ("Graduation Day, Part One").
 * Xander Harris has a deep hatred for all vampires, presumably because of the death of his friend, Jesse McNally.
 * One of the strains on the relationship between Buffy and Riley Finn is that he automatically assumes that all supernatural creatures are bad until he helps save the werewolf Oz from the Initiative, particularly after he witnesses his superiors' inhumane treatment of Oz while the latter was in human form ("New Moon Rising"). Soon after, he changes his mind.
 * Cordelia Chase initially believed that all demons, besides Angel, were evil until she discovered Allen Francis Doyle's Brachen demon heritage ("Hero").
 * Though the Scooby Gang and the Angel Investigations team are dedicated to destroying demons, they only seek to destroy evil ones. Both teams have employed the services of demons on several occasions, and many key members of both groups have been demons; in fact, during their time in Wolfram & Hart, the demon members of A.I. eventually outnumbered the human ones.
 * Gio, a rogue member of Gunn's Crew, led them on a fanatical crusade to destroy demons all over Los Angeles, regardless of their moral alignment ("That Old Gang of Mine").
 * Clem claimed that Rack had "a thing" against his demon species, though this is only mentioned and never shown ("Two to Go").
 * Willy the Snitch ran a neutral bar for all beings.
 * On multiple occasions, the U.S. government and its different groups show a desire to study supernatural beings and find a way to use their power for military purposes, the most prominent examples being the Initiative and its World War II-era predecessor.