Demonic Invasion, often reffered to by its TV Tropes nickname "Legions of Hell", refers to a doomsday scenario in which demons or similar supernatural beings launch an attack upon the world - often enslaving or massacring humanity (as well as possessing them).
This style of invasion has been popularised in media such as the Doom video-games and film - unlike Demonic Possession, a Demonic Invasion is an open conflict and often endangers a sizeable portion of humanity.
Demonic Invasion may also pave the way to Armageddon since it often breaks the balance of "good" and "evil" though many works that deal with Demonic Invasion portray devils as being capable of capturing worlds for an eternity if they desire - in essence transforming the world they have occupied into Hell.
The Shinto version of the afterlife is markedly different from the Christian version; thus, in anime not influenced by western notions of Hell and demons, Hell acts more as something of Lawful Neutral than evil regardless of how it looks, especially the classical Buddhist and Chinese versions. Demons will be more like administrators than tormentors, often taken to the extreme.
This trope is the evil counterpart to "Angelic Invasion"/"Armies of Heaven".
Fiction Dealing with Demonic Invasion
- Doom series
- Devil May Cry series
- The Legend of Zelda
- The Power of Five
- Middle-earth series
- Evil Dead series
- Warcraft III: Reign of Chaos
- Dragon Age: Origins
- Dragon Age: Inquisition
- Diablo series
- Gravity Falls