The Legions of Hell are usually portrayed as enemies of God, the Council of Angels, and everything that is good and true. Their existence is a bad thing for almost everybody; when they come out of Hell, they're doing it to break things and make the world a worse place. And, you know, corrupting people into evil and tormenting damned souls is usually a pretty nasty thing to do.
But sometimes, the demons are that way for a reason, and they're doing it with the express approval of the Big Guy Upstairs. They still torture and corrupt people, but the corruption and torture are portrayed as serving a necessary function in the grand scheme of things. When they attempt to corrupt humans, they're doing it as a way of testing humanity's faith, morality or both. When they torment the souls of the damned, it's because the damned deserve punishment and someone has to deliver it. In other words, they're basically a divine law-enforcement agency, laying down punishment on those who break the law.
This trope is Older Than Feudalism, and in fact predates the current conception of Satan serving as God's enemy. In the Hebrew Bible, Satan or Sammael was in fact an angel, whose duty was to test man and attempt to lead him into evil, as well as to destroy humans at God's command; in the transition to Christianity, the Devil morphed into a rebel against God and a being of pure evil.
A common subversion, or perhaps deconstruction, occurs when this trope is how the cosmos is supposed to work, but due to corruption, apathy, or a simple breakdown in communication, Heaven and Hell are in an adversarial relationship, to the detriment of a properly-functioning cosmos. Sometimes, the plot will even revolve around finding out what has gone wrong and fixing the situation.
This trope can overlap with Dark Is Not Evil, but not always. Sometimes Blue-and-Orange Morality is in play, sometimes God Is Evil, and sometimes, just serving a divine purpose doesn't exempt demons from being sadistic jerks. If God and Satan are specifically working together, it's God-Karting with Beelzebub if it's not Teeth-Clenched Teamwork.
No relation to Hells Angels.
- In the Sistine Chapel's altar painting, the infernal Charon is seen beating the damned into Hell in accordance with Christ's last judgement. This role comes straight out of Classical Mythology, but it fits awkwardly into Michelangelo Buonarroti's Christian cosmology, where demons are all rebels against God.
- The Digimon Manticoremon is a mindless demonic beast with an obsession for consuming the Always Chaotic Evil Virus Digimon like itself. For this reason, it's often used as an attack dog by angelic Vaccine-type Digimon. It makes its first anime appearance in Digimon Ghost Game where it went rogue but its angel master Darcmon shows up at the last second to stop the heroes from killing it and bring it back under control.
- Angels of Hell (see "Myths & Religion") appear in a book of the The Sandman (1989) continuum, where Lucifer tires of running Hell and, to fill the void, God sends two righteous Holy Angels down to take over and ensure things are running properly. The two Angels, out of a combination of self-righteousness and Jerkassery, end up making Hell a never-before-seen place of pitiless and unmitigated horror and suffering, convinced this is necessary to fulfill God's will...
- Discussed in Immortal Hulk, which compares and contrasts this trope with its counterpart, the devil as adversary of Heaven — the difference between the accuser in Heaven's service who scours and tests mortals (as with Satan in the Book of Job) and the adversary who seeks to destroy what God has created.
- Mercy Sparx follows a demon who has been hired as a Bounty Hunter by Heaven to bring in or kill rogue angels.
- A character in Jacob's Ladder (who is heavily implied to be an angel) explains that the entities in the film that appear demonic tormentors are actually angels trying to cleanse the souls of the damned that they may eventually ascend to Heaven.
- Downplayed in Little Nicky. Satan rules hell mostly because someone has to see to it that evil souls are punished, and he's simply the guy who's most suited for the job (after his father, Lucifer, grew too old and retired). His older sons Cassius and Adrian are evil to the core, however. His youngest son, Nicky? Not so much.
- The demons in Dark Angel: The Ascent are religious, and Hell is indicated to be working in concert with Heaven. They're not evil, just doing God's will punishing sinners.
- The Aeneid: The infernal Furies are sent away from their work in the Underworld by Juno, goddess of the heavens. She uses them to start a war between Aeneas and Turnus to delay Aeneas' fated victory, an unnatural plan that earns Juno Jupiter's reprimand.
- The Canterbury Tales: The Friar's Tale implies this, telling a story about a corrupt church Summoner making friends with a low-level demon. They come upon a frustrated coachman, who angrily tells his horses to go to Hell. The Summoner points out to the demon that this is effectively permission to go take the guy's stuff. The demon, however, points out that the carter didn't really mean it, and specifically invokes God's authority in his reasoning: "'Nay,' quod the devel, 'God woot, never a deel! It is nat his entente, trust me weel.'" note As the story goes on, we see that the Summoner is nowhere near so bound by the rules of fair play, and fully prepared to twist people's words, so at the end, the demon drags him off to Hell.
- The Divine Comedy: Virgil trusts the devils of fraud because his paganism has taught him that demons are agents of the gods' justice. The trope is Subverted when the Malebranche try to kill Virgil and his ward after lying to them about how to leave their torture-chamber. It's so foolish to think Fallen Angels would act justly that even a damned Hypocrite mocks Virgil for his blunder.
- Good Omens: Demons are still a part of the same Celestial Bureaucracy that the angels work for. The narration even states that both sides are just doing a job. While they will duke it out in Armageddon, it's because that's what it says in the "Great Plan".
- Incarnations of Immortality features the failed version. Supposedly, Satan is corrupting people and manipulating souls for the purpose of self-aggrandizement, while God is not minding the store, leaving the other Incarnations to fight against Satan's plots. In his own book, however, Satan is portrayed as a Punch-Clock Villain who has gotten tired of the system's breakdown, and is plotting a takeover so that he can update the system's definitions of Good and Evil, and stop souls who are supposed to go to Heaven from ending up in Hell. After the Incarnations defeat Satan's final plot, God is fired, Satan chooses God's replacement, and the system starts working again.
- Inferno (Larry Niven and Jerry Pournelle): The demons in Hell openly identify as servants of God, diligently working to reap justice without mercy onto the damned and take obscene pleasure in doing so. They even ask Carpent(i)er to relay the message to Heaven and its offices that they continue to serve faithfully.
- In "The Last Trump", by Isaac Asimov, the angel responsible for Earth is very much surprised to learn that the Devil is God's servant, since Good requires Evil to struggle against.
- The Metamorphoses: The Furies, Harpies, and other cthonic monsters Orpheus charms are agents of justice imposing punishment on wicked men. They may be intimidating, but they punish those who offend the gods and are not themselces tortured like Christian devils.
- Good Omens (2019): Like the book it's adapted from, demons and angels are two sides of the same Celestial Bureaucracy who oppose each other because that's what the Great Plan says. Unique to the series, this is compounded by the fact that Heaven and Hell are in the same office building.
- This appears to be the case in The Good Place. Although employees of the Good Place and the Bad Place tend to regard each other with disdain and distrust, it is nothing more than Interservice Rivalry. They are, at the end of the day, two branches of the same Celestial Bureaucracy and answerable to the same cosmic laws.
- The Book of Job in The Bible is the Trope Maker, where ha-satan ("The Accuser") is a member of God's divine council. When God points out Job as a righteous and virtuous man who has never turned away from Him, Ha-Satan responds that of course Job is a loyal servant of God; he has everything he could possibly want, and if he lost all of that, he would curse God and turn away from him. God agrees that Ha-Satan may put his claim to the test.
- The non-canon Book of Jubilees has an angel named Mastema, chief of the Nephilim who operates similarly to Ha-Satan above by punishing sinners and testing the faith of God's followers through a legion of demons under his command.
- Inverted in Islamic texts, where there exist angels of Hell. Their job is to prepare the fires of hell and later punish sinners.
- A quote attributed to Martin Luther, popular in some sects of Reformed Protestant Christianity, says, "Even the devil is God's devil." The point is not that The Devil is necessarily on the same side as God, but that God is The Omnipotent and therefore everything that exists, even the Devil, ultimately works according to God's plan. (Trying to describe how exactly this works in practice, though, has been the subject of much theological Serious Business.)
- The servants of Yama the Just in Hinduism take no pleasure in the torments they put sinners through in hell/naraka, but they do it because it must be done.
- The Thebaid: Oedipus' pious prayers for the death of his sons is answered by the heavenly King Jupiter by sending the Queen of the Pit, the Fury Allecto, to breathe hatred and envy into their souls.
- Ars Magica: This is one theory about why demons do what they do; even though they appear to be enemies of God, they are actually about God's work. The Avengers of Evil in particular claim to be about this, and they can make a fairly good case that they're telling the truth... but no one can ever be sure, since a demon's very nature is to deceive.
- Dungeons & Dragons:
- The Tyrants of the Nine Hells sourcebook recounts the baatezu's creation myth, which you can believe at your own peril. The story goes that the Lawful Evil devils are former angels who were created by the heavens for the purpose of battling the Chaotic Evil demons at the dawn of creation, and who took on some of the fierce and terrible traits of the demons to better understand how to combat them. This caused the other angels and good gods to shun them, but there was little they could do since the tainted angels were still acting within the bounds of the heavenly laws. Eventually Asmodeus, the leader of these dark angels, suggested that his devils could do the unsavory work of punishing mortals who invited demons into the Material Plane, but this quite ruined the atmosphere of the heavens, causing more friction. So Asmodeus struck the Pact Primeval with the gods of law, which set aside a dedicated Hell that his devils could punish sinners in, and allowed them to sustain themselves by torturing damned mortal souls for spiritual energy. For a while after that everything was great, and the heavens were free of the devils and their torments... until the good deities noticed that they were receiving fewer virtuous souls because the devils were tempting mortals into evil on the Material Plane. But when those gods confronted Asmodeus about this, he simply smiled and said,"Read the Fine Print."
- Forgotten Realms: Implied: the devils/baatezu have contracts with the god of the dead (currently the Lawful Neutral Kelemvor) that allow them to recruit unclaimed dead souls from the Fugue Plane (where the dead are sorted). Exactly what the gods get out of it is not explained, but it contrasts sharply with the demons/tana'ri, who occasionally mount raids on the Fugue Plane and simply kidnap the souls they want.
- In Nomine: This is how the Habbalah demons see themselves; though they live in hell, they say they're really undercover angels doing the hard-but-needed work of testing people and torturing sinners. Canonically, they're deluded (even by demon standards) madmen whose 'tests' are thinly-veiled excuses to hurt people, somewhat akin to performing quality control on luxury cars by smashing them with sledgehammers and then saying they're faulty when the body dents or the windows break. This is because Habbalah are fallen Elohim (angels of impartiality and fair judgement), meaning that while they retained their sense of self-justification, their judgement is completely consumed by their biases; the Habbalah start with the verdict of 'Humans Are Bastards' and come up with evidence after the fact.
- Vampire: The Masquerade:
- Part of the basis for the Lancea Sanctum is the Path of Night, a Path of Enlightenment which believes a vampire's purpose is to serve as an agent of evil in the service of the Powers That Be, tempting and horrifying mortals in order to test them, the weak falling and the strong tempered by their trials.
- Kindred of the East features the Howl of the Devil-Tiger dharma, who believe their role is to serve as replacements for the corrupt Yama Kings as devils in the service of Heaven. On the one hand, they are to punish (and make use of) humanity's greatest sinners; on the other, they are expected to act as befits their station in the Celestial Order, behaving as truly cultured and magnificent devils should.
- Vampire: The Requiem has a faction called the Lancea Sanctum. They're a group of vampires who believe that though they are damned and possessed by the demon-like Beast which drives them to evil acts, they are meant by God to scare and punish humanity through their depredations so they remain virtuous. This is, to say the least, hotly contested since it functionally pushes them to seek ways to harm humanity actively, albeit with more focus on the wrongdoing. Their mythology even tells of visitations by disapproving Angels when vampires fail to live "up" to their role.
- In Afterlife (1996), you need demons to run Hell just as much as you need angels in Heaven. Shortages will result in souls not being punished efficiently. However, too many unemployed angels or demons will get bored and eventually declare war on the opposing astral plane.
- Princess Maker 2's Prince of Darkness, Lucifon, is an example of this trope. In the very beginning of the game, the LORD tells him to attack the corrupt and decadent human kingdom and punish it for its sins. He accepted the LORD's will and attacked humanity, only to be defeated by an unknown warrior. In a discussion after the battle, he tells the warrior that he was Just Following Orders and "I killed only fools," a statement that the warrior has no answer to.
- Shin Megami Tensei has used this trope on occasion. Note that unlike most examples of this trope, God Is Evil in this setting.
- Shin Megami Tensei I mentions it in passing in the Chaos Ending, where Lucifer says that he himself is also a part of YHVH.
- In Shin Megami Tensei II, Satan is YHVH's Dragon and the most powerful demon of Law. On the Law path, he finally gets fed up with YHVH's bullshit and joins Aleph to take his boss down.
- Shin Megami Tensei IV: Apocalypse: God set up the Law Vs Chaos conflict (and split Satan into the Four Archangels and Lucifer) to keep humanity distracted and fearful; humans are actually the only species that can naturally Clap Your Hands If You Believe, so convincing them that they are under constant threat of being enslaved or eaten makes them pray to YHVH constantly, ensuring He remains all-powerful. That is, until one of the demons finally catches on...
- In Disgaea most angels and demons like to consider themselves as the pure good and pure evil respectively. However, the first few games seem to indicate that they're more like order and chaos but otherwise basically just people with wings and horns and such. The fourth game is the one that starts this trope by making it clear that angels and demons have their own roles based around the human worlds. While angels provide guidance, compassion and so on, demons are basically meant to serve as a boogeyman for humans: If humans stop being afraid of demons, they grow out of control and put themselves at risk of extinction. Thus, angels feed off faith and prayer while demons are sustained by mortal fear to make sure everyone does their job properly. The villain is actually disrupting this system by making humans independent enough to fear each other more than demons, which means the demons lose power and can't make humans behave themselves. Demons seem to thus hold to certain standards, even helping out when they consider it necessary, and offenders of these standards are held in contempt.
- Implied with Chris Kyle from Monster Lab (2021). While he's referred to as "God's holiest angel" even by God himself, his ability to possess people and his demands for blood sacrifice imply ... something else.
- In Dimension 20: Fantasy High, the pit fiend Gorthalax the Insatiable is an affable fellow and an excellent father who explains that the Nine Hells exist to punish evildoers, and many people only don't commit evil deeds because they lack the opportunity to do so. Thus, Gorthalax and other devils see it as their job to trip wicked mortals up through temptation, so that bad people don't "backdoor their way into Heaven".
- This is actually pretty close to how Satan and Hell are portrayed on South Park. Satan is actually one of the more level-headed characters in the entire show, and he sees the tormenting of sinners as just a job he does with the temptation of mortals being necessary to ensure free will. Then again, it's also shown that, in the South Park universe, everyone goes to Hell except for Mormons. Even though God is a Buddhist.