Fiends of the Underhell
- Always Chaotic Evil: Underhell fiends include some lawful and some chaotic creatures, but all are the purest of irredeemable evil.
- Dread Zeppelin: To ensure their mastery of skies in the worlds they inhabit, Styx fiends construct massive airships made of burning iron called hellkites. Able to dart through the air with fiendish magic and a precise control of thermal currents, a hellkite can bear hundreds of maggots or dozens of more powerful fiends.
- Hellhole Prison: Dis maintains larger prisons than most other legions, and carefully inflict exquisitely painful mutations to increase their captives' suffering. Victims that have been too long in these prisons become wholly unrecognisable to their allies.
- Made of Iron: Fiends of the Annwn Legion demonstrate a phenomenal resilience unmatched by any other legion. Most Annwn fiends are incredibly resistant to blows from mundane weapons and can even shrug off damage from nonmagical dangers like siege engines.
- Mordor: The Acheron Legion exemplifies decay, desolation and gloom. Lands controlled by this legion are barren; vegetation rots and dies, and animals are sickly and bear only dead, misshapen offspring. The light is gray and everything is washed out. A stomach-churning stench permeates the land, fouling the scarce food and water that remains. Even creatures who find something to eat in a land ravaged by this legion's touch often can't keep it down. Food and drink brought into the area quickly spoil, emitting the same ghastly stench as everything else.
- Our Demons Are Different: The fiends of the Underhell are beyond clear categorisation into chaos, law and conventional neutrality, or even the natural laws of the understandable universe. They demonstrate a clear organisation within their legions, serving their Archlords and the leaders of their legions, but are individually reckless, violent and fickle. Even their very physical forms are unpredictable: indeed, it is difficult, even dangerous, for mere mortals to even look upon the forms of Underhell fiends. Two possible answers are presented for their origin, each appropriate for a different sort of cosmology:
- If the Archlords and their fiends are a known type of fiend, the Underhell is simply a remote region of the an existent evil plane. The fiends have long lurked secretly in remote parts of the plane in question, but now they have suddenly emerged with overwhelming force. In this campaign, the fiends are likely to have allies from better-known fiends.
- If the Underhell represents an entire lost plane of existence of primordial evil beneath the deepest, darkest pits of the known evil planes, remote from the Material Plane, its denizens are progenitors of evil as it is currently known, or maybe they are evils that have survived after being driven away by the known fiends, fearful of their singular cruelty and cohesion. Now, circumstances have unlocked their primeval prison. In this campaign, the fiendish invasion consists mostly or completely of monsters from the Planet Apocalypse book and is likely feared even by other fiends, who might unexpectedly decide to help the heroes.
- Required Secondary Powers: Tartarus fiends often drip with poison or transmit virulent plagues, to which they are immune.
- Roaring Rampage of Revenge: Creatures of spite and malice, fiends of the Cocytus Legion believe no insult should go unpunished and revenge should be served a hundredfold. They hold grudges with a near-religious fervour and scheme to heap revenge against any dissent or slight, whether real or imagined.
- The Social Darwinist: Underhell legions are built upon the strong exploiting the weak, while the weak struggle to find an opportunity to exploit their peers in a bid to rise above their station and overthrow those who have abused them.
- Supernatural Fear Inducer: Lethe fiends can instill such an overwhelming horror that onlookers are wholly unable to act.
- Teeth-Clenched Teamwork: Cohesion within the Cocytus Legion is relatively weak, as fiends exact vengeance upon each other as much as they do their enemies. A powerful leader can compel Cocytus fiends to work toward a specific goal in the short term, but infighting is inevitable under weaker leaders. Wise adventurers learn to prey upon this infighting, as it means squabbling bands of Cocytus fiends aren't likely to come to each other's aid.
- True Sight: Fiends of the Sheol Legion have a magical sight that comes in a variety of forms. Some Sheol fiends can see magical auras, others can see thoughts of sentient creatures, and still others can sense hostile intentions.
- We Have Reserves: In any case, 'killing' Underhell fiends is really just a banishing, and the same fiend will soon enough return to the mortal world through another Doomgate. So long as they focus on destroying fiends, the PCs can only slow down the flood temporarily; the tides of invasion are literally endless. With limited resources, the PCs must make progress against their plans in other ways. Fiends should taunt heroes with this fact, promising to exact painful revenge when they return to the world.
- Wreathed in Flames: Phlegethon fiends are always surrounded by hellfire. The least of the maggots and fiends have fire that dances upon their shoulders and arms, while the most powerful fiends are surrounded by sheets of fire like a cloak, and many wear a crown of flame.
- You Have Failed Me: Annwn leaders are obstinate and quick to punish subordinates who fail to measure up to the legion's reputation. They consider giving even an inch of ground to be an embarrassing loss, and most Annwn fiends that flee a battle defect to another legion in order to conceal their shame.
- Zerg Rush: Far more than any other legion, the Hades Legion employs massive hordes of maggots and slaves to do its fighting.
Maggot
- Cannon Fodder: Broken maggots know little other than how to surge ahead and smash things apart with their fists. Fiends consider them to be even more expendable than other maggots, and most are surprised when a broken maggot survives a simple or straightforward assault.
- Demon of Human Origin: Souls who fall under the sway of the Underhell are hung up to cure like meat, tormented, twisted, and reshaped until virtually nothing of their original thoughts or purpose remains. The shattered souls take on a physical form shaped from the final vestiges of the soul's sense of self. Called void maggots, these broken soul-things exist only to serve other fiends.
- Dumb Muscle: The Dis Legion focuses on mutation, degeneration and regression to brute, animalistic impulses. Low-ranking Dis fiends are generally the most straightforward and stupid, as they do not prize thoughtfulness or foresight.
- Gladiator Games: Gehenna fiends enjoy brutal and bloody arena sports and often arrange these sorts of fights when there isn't anything more interesting to capture their attention.
- Sycophantic Servant: Simpering maggots constantly fawn for their masters' favour and compete against each other over scraps or compliments.
Gryllus
- Gold and White Are Divine: Invoked. As a sign of their power and prestige, shining grylluses prefer to wear white and gold.
- The Hedonist: Leering grylluses have a voracious appetite for hedonistic pleasures like rare wines, fine food and powerful drugs, which they consume almost as quickly as they can get them.
- Small Name, Big Ego: Even the lowliest gryllus considers itself to be a noble creature of the highest order. Grylluses consider themselves to be clever conversationalists with enviable wit, but their 'cunning bon mots' are merely blunt insults and their 'sophisticated wit' is nothing more than mean-spirited pranks. Ceaseless gluttons, grylluses purport to have a refined palate but instead merely gobble up any food or drink put before them while smacking their lips and muttering about 'fragrant notes' and 'exquisite piquancy'.
Underfiend
- Big Red Devil: To many mortals, underfiends epitomise the forces of the Underhell: tall, muscular humanoids with horned heads.
- Blood Knight: Underfiends consider themselves soldiers first and foremost. They rarely waste time tempting mortals or engaging in infernal politics, and chafe at being commanded to serve in any idle position, such as guard duty.
- Dressing as the Enemy: Skincloak underfiends possess the supernatural ability to tear the flesh from their humanoid foes and wear it as a disguise. This ploy rarely works for long, as underfiends do not have a flair for deception and the magical disguise fades quickly, but this is frequently enough to get them past guards or front lines, where they can revel in the slaughter of the innocent and unprepared.
- Sapient Eat Sapient: Flesheater underfiends engage in gruesome ritual eating of the dead, and often do so while in the middle of battle to unnerve the allies of fallen victims. Although they are no more cruel or brutal than other fiends, their spontaneous cannibalism gives them a grim reputation.
Cacodemon
- Bad Boss: Cacodaemons frequently set their minions against each other for their own amusement when they lack mortals to torment. In combat, most lesser fiends are happy to let a cacodaemon die to avoid suffering under its wanton moods.
- Demonic Possession: A shrieking cacodemon can force its soul into the body of a mortal. It can be surprisingly clever about impersonation when it knows the stakes are high, but most of the time it remains silent. The shrieking cacodaemon knows its control can easily be broken by damaging the host, so it prefers possessing targets that can stay far away from allies.
- Supernatural Fear Inducer: Simply being aware of the presence of a cacodemon can frighten creatures as the cacodemon desires.
Fourth-Circle Fiend
- Death-Activated Superpower: When a fourth-circle fiend of the Cocytus Legion dies, it curses all non-fiends within 90 feet.
- Mini-Boss: In the board game, fourth-circle fiends act as mini-bosses who often boost or modify the map or the other minions.
Bellatrix
- Eyes Do Not Belong There: A bellatrix's woman-like body has no head nor limbs, but rather eyes where the stumps terminate.
Catoblepas
- Death-Activated Superpower: When a catoblepas falls apart completely, it unleashes a toxic wave that fills the region for miles around with poisons and diseases, quickly killing most plants and wildlife and leaving a persistent stain on the land.
- Plague Master: A catoblepas is a physical embodiment of rot. It spreads pestilence wherever it goes, enjoying the process of living mortal flesh eroding over time.
- Walking Wasteland: A catoblepas slowly crumbles as it moves, dropping bits of flesh and ichor behind it. This toxic residue saturates the regions it passes through with a variety of diseases and poisons that infect mortals.
Cendiary
- Wreathed in Flames: Hellfire pours from a cendiary as it rolls, igniting anything it touches and providing a shimmering nimbus around it. This hellfire harms neither the cendiary nor any nearby fiends.
Gadarene
- Full-Boar Action: The gadarene is a vaguely humanoid, boar-like monster that walks on two forelegs.
- Supernatural Fear Inducer: Merely glimpsing or hearing a gadarene's movements fills all living things with existential terror.
Hell Hound Alpha
- Breath Weapon: The hell hound alpha can exhale a cone of fire from its jaws.
- Hell Hound: The hell hound alpha generally resembles a monstrously large wolf in its lean, quadrupedal posture. Far more cunning than a mere canine, it possesses a pyromaniac's heart.
- One-Steve Limit: This creature is renamed hell hound alpha in the RPG supplement, to distinguish it from the classic Dungeons & Dragons hell hound.
- Playing with Fire: The hell hound alpha is a master of fire creating a burst of fire every time it steps and breathing fire from its mouth.
Hortator
- Drums of War: Hortators are infernal drummers that inspire groups of lesser fiends to ruin and fight with all their might. The quick drumbeat resonates and quickens the pulse of all fiends while stilling the blood of mortals.
- Mook Commander: As long as a hortator is not incapacitated, its incessant drumming grants all other fiends within 1 mile that can hear it advantage on all attack rolls and additional thunder damage with weapons. Hortators make their fellow fiends dramatically more dangerous, even at a great distance. In an encounter in which a hortator's Fiendflesh Drum can be heard, each other fiend has its challenge rating increased by 1.
Magdalene
- Enemy Summoner: A magdalene functions like a supplemental Doomgate, limited to allowing void maggots and similarly minor fiends to travel through it. This magic makes it extremely dangerous if left unchecked, because it can swell an invading fiend army's common infantry quickly.
Mandrake
- Capture and Replicate: A mandrake can create copies of people, which can duplicate the original creature's mannerisms precisely but are as evil as their creator, to work its evil will in the world. Hostages rescued from a legion led by a mandrake may have one or more duplicates among their midst, intentionally sent back to serve as saboteurs to undermine the legion's next targets.
Nuckelavee
- Teeth-Clenched Teamwork: Since nuckelavees are completely willing to steal the good luck of its allies, other fiends tend to dislike them, and they are usually encountered alone.
- Vertebrate with Extra Limbs: The nuckelavee is a quadruped with a pair of arms.
- Winds of Destiny, Change!: A nuckelavee can steal the luck of other creatures, friend or foe.
Philter
- Armless Biped: A philter has no lower body, and its head and torso walk on long-fingered hands.
- The Medic: The philter and each of its allies that can hear its dirge regain 10 hit points at the start of their turns.
Raparee
- Belly Mouth: A leering face adorns the underside of a raparee's thorax, which constantly makes a wet burbling sound that unsettles enemies.
- Beware My Stinger Tail: The raparee can inject poison from the paired stingers at the ends of its body.
- Laser-Guided Amnesia: The raparee is a consummate thief, plucking 'valuables' from its victims with supernatural agility. What the raparee considers 'valuable', however, is rarely gold or magic items; instead, it prizes more ephemeral items, such as memories of the victim's children, sense of taste, or ability to see a colour. Although their loss is rarely debilitating, the missing memories are both distracting and unnerving as well as emotionally painful.
- Multiple Head Case: Two heads protrude from the front of a raparee's body.
Secutor
- Blade Below the Shoulder: One of a secutor's long arms plumes out into a chitinous shield, while the other ends in a wicked hook that scrapes along the ground.
- Deadly Gaze: When a secutor comes upon lesser mortals, a simple glare from it kills them where they stand.
Tardigrade
- Determinator: A tardigrade is as relentless as it is resilient. When it sets its mind on a particular task, it proceeds doggedly with its plan, even if it is slain over and over in the attempt. The tardigrade is not a mindless brute, however, and it learns from its past mistakes, changing its plans to improve its chances of achieving its goal.
- Your Soul Is Mine!: A tardigrade collects souls from victims slain by its razor-sharp claws.
Underhell Elemental
- Elemental Embodiment: Instead of fire, water, air or earth, Underhell elementals consist of far more horrifying building blocks: bone, gristle, hellfire, iron, and others.
- Invisible Monsters: An Underhell elemental can physically unmake itself and allies for a short time. Creatures that are unmade become invisible and can pass through solid objects with effort, but can still be heard. This ability is used to stage ambushes and gather information.
- Magic Music: The Underhell elemental hums a magical tune that entrances non-fiends that hear it.
Apocalypse Undead
- Acid Attack: Leaping skins constantly seep unique acids from their pores that break down the tissue of any creature it engulfs, effectively allowing a skin to digest a creature.
- Combat Tentacles: The restless grow strange protrusions of writhing flesh-like small tendrils that grasp nearby creatures and interfere with enemy attacks.
- Helping Hands: The energies of the Underhell can animate extremely damaged corpses and body parts. These remnants are known as shambling fragments, due to their discordant movement.
- Hive Mind: Through the power of the Underhell's fell energies, many mass graves become the site of large, undead uprisings. In rare cases, these corpses rise in the same instant, creating a sort of hive-mind or shared consciousness. These corpses move in unison as large masses of undead known as crawling hordes.
- Horror Hunger: The restless constantly hunger for flesh and are searching for something to consume. It is not uncommon for a restless to rise and immediately consume any others with which it was buried. Once they have fed on nearby corpses, restless move on in search of more flesh, never satiated by their meals.
- Night of the Living Mooks: As Underhell fiends move throughout the world, corpses soon rise again, the vile power of the Underhell animating them once more. These undead are mockeries of the victims of the fiends of the Underhell, who are all too happy to allow the undead to consume and destroy as they wish.
- Non-Human Undead: The Underhell has created undead ashen angels from the corpses of fallen celestials.
Corrupted Creatures
- Anti-Regeneration: Acheron-corrupted creatures exude an aura of deterioration and lifelessness that prevents creatures other than fiends and Acheron-corrupted creatures from healing.
- The Bully: Gehenna-corrupted creatures bully others as they were bullied.
- Deal with the Devil: Most often, Underhell corruption occurs willingly: a desperate creature submits itself to the fiends and offers its loyalty in exchange for revenge, power, or just survival. A fiend can be whimsical when entertaining such requests and might simply obliterate one prospective supplicant while corrupting another. When the corrupted creature dies, its soul is forfeit to the legion or Archlord that corrupted it.
- Demonic Possession: A fiend that has lost its physical form might possess another creature, feeding the creature's worst impulses and altering how it sees the world.
- Emotion Bomb: Lethe-corrupted creatures impart the self-destructive feelings of desperate loneliness with their attacks.
- Glowing Eyes of Doom: Pandemonium-corrupted creatures usually have a violet glow to their eyes that grows brighter when they cast spells.
- Good Scars, Evil Scars: A Cocytus-corrupted creature sprouts glowing, angry-red scars upon its flesh that represent the grudges it holds.
- Last Chance Hit Point: If a Hades-corrupted creature is dropped to 0 hit points by a non-critical hit, it has a chance to stay at 1 hit point.
- Made of Iron: The Annwn legion's magical energies can warp the physiology of nearby creatures, imparting the same remarkable durability of Annwn fiends.
- Power Gives You Wings: Styx-corrupted creatures become particularly agile and sprout wings of some variety.
- Wreathed in Flames: Phlegethon corruption manifests as wispy flames across the corrupted creature's body, which it can focus into an immolating breath.
Nephilim Engines
Corpse Mother
- Flesh Golem: The corpse mother is a construct made from hundreds of corpses, which traverses battlefields left ravaged by the armies of the Underhell, collecting corpses and adding them to its own body.
Racked Seraph
- Playing with Fire: A racked seraph's gaze can cause other creatures to catch fire.
- Your Soul Is Mine!: When a racked seraph kills a creature, its soul can become trapped in the racked seraph until the racked seraph releases it or is destroyed.
Animated Doomgate
- Flunky Boss: An animated Doomgate can use some of its own energy to call upon individual beings from the Underhell to protect it. This effort is taxing, however, so an animated Doomgate only calls other creatures when necessary.
Siege Dragon Engine
- Base on Wheels: Minions of the Underhell build simple battlements, towers and walls on the backs of siege dragon engines, allowing them to travel securely across a battlefield.
Fiend Lords
- Cool Crown: Most Archlords wear one or more Crowns of the Underhell which levitate above their heads and help them maintain the interdimensional anchor required to allow an entire fiendish army to invade the mortal world.
- Demon Lords and Archdevils: Fiend lords are the most powerful fiends, above the conventional circles of authority. They use their unmatched might and magical resources to demand the obedience of whatever fiends are useful for their current goals.
- Fighting a Shadow: Archlords sometimes create avatars, which are temporary, separate creatures with the same desires and goals as the Archlord and power akin to a lesser fiend lord. Avatars allow Archlords to be in multiple places at once and engage dangerous foes in battle without risking their own physical forms. Creating an avatar is a taxing process, so typically an Archlord can only create one during an invasion.
- Final Boss: In the board game, the Archlord is the final obstacle the players have to overcome before they could close the Doomgate and save the world. The players win when they kill the Lord in a Lord Battle.
Argus
- Eyes Do Not Belong There:
- Argus has eyes all over his body and bulging from a growth on his chest.
- Argus' presence causes fleshy ground to spread across the land. Every patch features an eye of varying size and origin, through which Argus can see.
- Information Broker: Argus sells to other Archlords information that he doesn't think can be used against him.
Asmod
- The Hedonist: Lord Asmod embodies careless overindulgence, willful negligence, and use of pleasure as a weapon of evil. His domain in the Underhell is filled with all sorts of hedonistic pleasures twisted to evil and cruelty.
- Multiple Head Case: Ten tusked, crocodile-like heads emerge from Asmod's shoulders.
Baphomet
- Baphomet: Baphomet is an Archlord who resembles a huge skull protruding from a stone wall.
- Belly Mouth: A mass of entrails ending in a fanged mouth extends from Baphomet's stomach.
- Broken Armor Boss Battle: Baphomet is embedded in a magically mobile wall that serves as a conduit for fiendish power. The wall can be attacked separately, and destroying the wall weakens Baphomet.
- Evil Is Not a Toy: He takes a special perverse joy in creating a Doomgate out of those who learn the nuances of evil magic in order to fight evil.
- Playing with Fire: Baphomet's Breath Weapon is a cone of hellfire, and his presence causes hellfire to spread across the land.
Chthon
- Attack! Attack! Attack!: Chthon's invasion is a chaotic tide with little direction other than toward whatever gleams most brightly on the horizon.
- Unstoppable Rage: Lord Chthon is white-hot hatred and jealousy embodied. He endlessly rages against all the beauty of the mortal world that he cannot have, and at the fiends who dare defy him. This makes him exceptionally deadly to cross but also short-sighted.
Geryon
- Chronic Backstabbing Disorder: Geryon's presence causes creatures to become willing to betray those who trust them and help traitors in exchange for any cut of the spoils.
- Cognizant Limbs: Geryon has three bodies, each with its own health bar. When a body is slain, Geryon can no longer make the attack corresponding to that body.
- Multiple Head Case: Geryon has three connected bodies, each with its own head.
- Split Personality: Each of Geryon's three aspects is both psychically linked and intent on different goals, willing and able to betray the others to see Lord Geryon become the Archlord that aspect desires. One wants to become master of illusion magic and pretty falsehoods; another wants to form an alliance of fiends to storm the good planes; and the third wants to become a dark god of murder and secrets.
Humbaba
- Multiple Head Case: Humbaba has three heads: a leering, humanoid visage and two grinning equine skulls.
- Plague Master: Humbaba's presence causes pestilence to spread across the land and diseased creatures to proliferate.
- Super-Empowering: Humbaba can instantly transform the essence of a gryllus near him into a bonestrike underfiend.
Jabootu
- Emotion Bomb: An embodiment of despair, Jabootu demoralises any creatures he encounters before finally finishing them off.
- Ultimate Blacksmith: Jabootu is a forge and smith of the living protomatter that composes the Underhell, and is responsible for crafting several evil artifacts and magic items, most notably the crowns of the Underhell.
Orobas
- I Shall Taunt You: If he is winning too easily, Orobas taunts foes with courses of action they haven't thought of, even if that information might prove useful to them.
- Suicidal Overconfidence: Orobas is so certain of his own indestructibility and so pleased with his superiority over mortals that he constantly wants to show off his boundless resources and powers. He doesn't consider the possibility that he might lose, and he will never retreat.
Procrustes
- Alien Geometries: In Procrustes' Shadow, space stretches and twists even more than usual for an Archlord's Shadow, and remains warped indefinitely after his departure.
- Gravity Master: Procrustes can reverse gravity in a 20-foot radius, 10-foot high cylinder, causing all creatures
Pulgasaur
- Collector of the Strange: Pulgasar obsessively collects rare novelties from among the ruins of the mortal world. His Underhell vaults are legendary for their troves of artefacts from a dozen worlds.
- Metal Muncher: When Pulgasaur is hit by a metal weapon, he bites it after it deals damage to him. If the weapon is nonmagical, it is instantly destroyed.
- One-Winged Angel: Pulgasaur is reborn from his own corpse when he is killed, each time stronger than the previous. He must be defeated three times to be truly banished, and he can only be truly killed if he dies three times in the Underhell.
Scylla
- Healing Factor: If her snake heads die, Scylla continuously regrows them, requiring no action on her part.
- Multi Tailed Beast: A fan of serpentine tails spreads behind Scylla.
Spider Mastermind
- The Man Behind the Man: When he leads an invasion, the Spider Mastermind often makes it appear another Archlord is responsible. To truly end the threat, heroes must deduce the Spider Mastermind's involvement from clues.
- Only Known by Their Nickname: The Spider Mastermind's true name is a closely guarded secret recorded only in lost and cursed tomes remote from the known world.
Stheno
- Acid Attack: Stheno's presence can cause acid rains to occasionally strike the nearby area.
Stroma
- Disproportionate Retribution: Lady Stroma is obsessive spite personified. She watches constantly for any slight against her, real or imagined, and then plots disproportionately grand retribution to ensure none who witness it ever considers standing against her again.
Tarasque
- Blood Knight: Tarasque embodies destruction for its own sake, and constantly harasses other fiends, destroying their works and fortifications to prove his own dominance.
- Hellfire: Hellfire spreads across the land and remains indefinitely after Tarasque's departure.
Filudo
- Eldritch Abomination: No one knows why Filudo has long been associated with the Underhell, since it did not originate there, but travelled from elsewhere. One theory is that Filudo comes from the mythical Forever Well—the source of all the multiverse. Presumably, it was either created as a universe itself, though a sentient one, or it crawled through the well from a different multiverse—a concept outside the understanding of most mortal minds.
