Demon

Overview

A Demon, also known as Daemon, is usually an evil entity borne from Hell, at least in Judeo-Christian religions. There are many different types of demons and they are usually depicted in a variety of ways, from flaming, horned brutes intent on destroying humanity, to beautiful, female demons who instill lust into the hearts of men, to more bizarre and strange forms, such as bird men or many-armed, many faced warriors. Whatever their origin, demons are to generally to be distrusted and feared in equal measure.  
 

Mythology

In the real world, demons and stories of them go all the way back to ancient times, possibly before written lore was even invented. Every culture has them and they are one of the few supernatural entities which have withstood the test of time, with even recent popular culture depicting them. Throughout history they have been both worshiped and feared, especially during the rise of Christianity when demons were considered to be a powerful evil force, able to possess both animals and humans and torment them to death unless driven out., usually by exorcism or, you know... death. Sometimes they can be mindless, causing havoc before being cast back down to the pits of Hell, and on other occasions they can be all-knowing and powerful, recruiting demonic armies and besieging man-kind. It is not known exactly why demons despise humans so much; some depictions show the demons wishing to escape Hell and live a more sheltered life which a human host can provide. Demons are closely linked with the Devil, who supposedly directs them, which may be another cause. 
 

In Games

Demons have been portrayed in numerous video games, usually as antagonists; Dante's Inferno, Darksiders,  Diablo, Doom,  Dragon Age Origins, Jade Empire, Prince of Persia, and World of Warcraft to name but a few popular games containing demons. In some games demonic powers can be harnessed and can even become a part of your character, as in Devil May Cry 4, while in some games, demons are produced in ways other than being spawned from Hell, as in the case of the character Devil from the Tekken series, who has DNA from the Devil himself inside him.
 
Because demons are open to such interpretation, they make exceptionally good boss characters, with many demon games utilizing them, or at least an archdemon form, as a significant challenge for players to overcome. Other times, they are simply placed in a game to scare and/or disturb players, such as with Demonic babies. Often, demons can be used to pose challenges or riddles to be solved - some demon's don't have the destruction of man at the top of their list, instead choosing to test them and meddle in their affairs; an example of this can be seen in Fable's demon doors. Occasionally, characters in games are possessed by a demon or demons, as in Dragon Age Origins and Jade Empire, where even small children are gifted extraordinary strength and persuasion. In the case of Dragon Age Origins, which has numerous demons throughout the game, the child was possessed by a desire demon, which had to be destroyed via an ancient ritual. 
 

This leads to the types of demons. Generally there can be many different types, but usually they fall into one of four groupings, as depicted in the Warhammer world (although not necessarily with these titles): Nurgle, the demons of plagues and pestilence; Khorne, blood-thirsty demons intent on the death and suffering of humanity; Tzeentch, demons of change who alter beings and life; and Slaanesh, the demons of lust and sexual sin. These can also be closely associated with the demons of the Seven Deadly Sins, being Lust, Wrath, Gluttony, Sloth, Envy, Greed and Pride, for example the sloth demon who is slow moving and docile as the name suggests. 
 
In the Elder Scrolls franchise, demons are given a more ordered look with the Daedra from Oblivion. Again, they each have different characteristics and goals, but each controls their own plane of Oblivion and their own army of demons and creatures such as Daedroths and Dremora. Some are relatively harmless, while others in the Daedric realms seek to destroy the world of man. Oblivion, the other-world they inhabit, is depicted in a typical Hellish style, with lava flows, poisonous plants, traps, variable landscapes and constructions and roaming demons.