Devils are the Iron Gauntlet wrapped in the Velvet Glove. They are the ultimate black market dealers on a planar scale. Mephistopheles to Faust, Lucifer to Christ, and the Devil to Robert Johnson.
The Devils of Hell are bureaucratic, lawful, and almost universally irredeemably evil. They are born from the souls of evil mortals that are thrown into the lower planes, and forged by the heat of hellfire.
Some are fallen celestials, cast out of heaven for their sins and now railing against the system that banished them from light.
It is better to rule in hell, than to Serve in Heaven!
Index Diabolus (the List of Devils)
Below is a list of Devils in Pathfinder First Edition from the d20PFSRD listed by their CR, followed by a list of Devils as they are ranked in Pathfinder Second Edition from the Archives of Nethys.
Pathfinder 1st Edition
Devils in Pathfinder 1st Edition have a strict Hierarchy they follow from the lowest Lemure to the highest of the Pit Fiends. Devils will follow orders and hierarchies to the letter, as befits their lawful nature.
When a mortal enters Hell, they start as a Lemure and over the course of time will grow and morph into more powerful demons. Theoretically, they could also make a “lateral” shift to a Devil type of the same rank as a sort of “career shift” over time.
Provided nothing happens to stop their growth through the ranks of Devils (provided they are clever enough), they can reach all the way up to the rank of Pit Fiend. Though this process can take centuries of careful planning and plotting.
Devils typically have two names: one being a title or epithet like Memory Devil or Tormentor Devil, and the other being a more formal name summoners use to call on these Devils for deals.
Unless otherwise noted, all Devils have these Traits:
Devils are lawful evil outsiders that hail from the plane of Hell.
Devils possess a particular suite of traits (unless otherwise noted in a creature’s entry).
- Immunity to fire and poison.
- Resistance to acid 10 and cold 10.
- See in Darkness (Su) Some devils can see perfectly in darkness of any kind, even that created by a deeper darkness spell.
- Summon (Sp) Devils share the ability to summon others of their kind, typically another of their type or a small number of less-powerful devils.
- Except when otherwise noted, devils speak Celestial, Draconic, and Infernal.
- A devil’s natural weapons, as well as any weapons it wields, are treated as lawful and evil for the purpose of resolving damage reduction.
Doll Devil (Arusities)
“A flawless female face that looks like porcelain stares blankly at you. Her small form is decorated with two black buttons for eyes, dark red lips, and braided raven hair topped by a red ribbon. She wears a simple schoolgirl’s outfit.”
Think Annabelle from the Conjuring Movies. These Devils specifically exist to tempt and prey on children and corrupt them into evil acts while young.
“A roiling wave of flesh gushes forward. Amid the fatty surge wriggle half-formed limbs and a dripping tumorous face.”
The lowest of the low, these are mortals who have been condemned to the Nine Hells for their sins. Over time, their torment turns them into these horrid creatures who serve other devils above their station.
“This vaguely humanoid creature is about as tall as a human and has clawed hands and dark grayish-black flesh. It wields a spear in its clawed hands.”
Should a soul fail to transform into a Lemure, they become these sorry beings. They are mostly treated as fodder for Hell’s massive armies.
These devils are small scavengers rarely seen outside of the Nine Hells. They aren’t even summoned all that often by evil spellcasters. Often they are found in swarms and attack in overwhelming numbers.
“Fiendish wings and a whipping scorpion-like tail lash behind this diminutive, red-skinned nuisance.”
The iconic little familiars, these buggers are typically sent out to the material plane to tempt beings to evil or be a nuisance for Hell’s enemies.
Accuser Devil (Zebub)
“This childlike blasphemy conjoins the features of a plump human infant and a gigantic, gore-fattened fly.”
Spite-filled and grotesque little devils. They often act as messengers for other Lords of Hell, and are sometimes sent to wreak havoc on the material plane.
“This small devil is black as night and wears a small red hat. A wicked grin flashes black teeth, and the creature nervously wrings its hands, bearing long needle-like claws.”
Hell’s accountants and record keepers, Ink Devils are craven and cowardly by nature. Most often they will use their cunning and wits to get out of fighting or lay traps for their enemies.
Lesser Host Devil (Gaav)
“This tangle of scaly avian limbs furiously beats its double pair of vulture-like wings, keeping its fiendish, horned skull-head aloft. As fetid breath rises from its repulsive, fly-covered visage, clawed arms work together to slash the air with a vicious-looking spear.”
These creatures hunt out souls who may have tried to escape from their specific circle of hell. They hound those souls they can find that are out of place, and drag them back to their torment.
Accomplice Devil (Hesperian)
“This robed figure appears human except for snakelike eyes, a pair of devilish horns, and the occasional dart of a forked tongue.”
Devoted Devils that serve the Archdevil and dark god Asmodeus. They are sent out among mortals to tempt the already important and prideful people down the path to further evil.
Pretender Devil (Dissimulare)
“With eyes of deep azure and sun-colored wings that glint in the fiery glow of its longbow, this humanoid creature emanates celestial radiance. The creature’s shimmering skin reflects light from the constant halo surrounding it, softening the small, jagged scar that mars its otherwise angelic features.”
Devils who pretend to be Angels or messengers from the Heavens. True Seeing can pierce this illusion and show the monster for what it truly is.
Addiction Devil (Atropocustra)
“This colorful, lean, anthropomorphically female damselfly with stunted wings possesses leafy hair, a sinuous barbed tail, goat eyes, hooves, and spiral horns. A motley of hops strobili and fungal caps pepper her shoulders and upper body.”
These Devils are experts in chemical addiction and temptation. They whisper in the ear of characters, and manipulate people to get them hooked on substances that destroy them slowly.
Bearded Devil (Barbazu)
“This seething devil deftly wields a vicious, saw-toothed glaive, while below its toothy maw writhes a hideous, twitching beard.”
These are the elite monster troops of Hell’s Armies. They are the battlefield commanders, leading squads of hellish Devils in their myriad wars.
Hellstoker Devil (Marnasoth)
“This man-sized creature has loosely hanging, rubbery flesh, grayish-black in color, and its entire body is smeared with a yellowish-brown mucus. Its head is ovoid, devoid of hair, and sports upward curving horns. A hardened ridge of bone runs from its brow, across the top of its head, and disappears into its spine. Its long, serpentine tail is dark grayish-red.”
These Hellish workers maintain the furnaces deep in the bowels of the Nine Hells. They rarely leave the lowest levels of the Plane, but when they do, they are typically hunting for more fuel for their fires.
Memory Devil (Mnemor)
“This ghoulish figure wears a tattered robe and stares with milky-white eyes, a proboscis-like tongue snaking out over its distended jaw.”
Mnemor Devils specifically deal with Memory. They will take memory and secrets from willing (or unwilling) mortals who find them too painful to remember, and use them to torture others.
Greater Host Devil (Magaav)
“Twin pairs of mangy, disease-riddled vulture wings flap in concert, keeping this lean raptor fiend aloft. Twisted horns rise from a head like a monstrous skull and noxious fumes leak from between its yellowed fangs. Hovering with impossible control, its vicious foot talons clench and unclench, while its clawed hands wield a long, three-pointed ranseur.”
The greater versions of the Gaav devils above. These monsters range farther afield, looking for even more powerful wayward souls. Sometimes they range all the way to the material Plane.
“A beautiful well-proportioned woman with crimson skin stands before you. Her eyes are dark, almost black as is her hair. A pair of small bat-like wings protrudes from her shoulders. She wields a gleaming longsword in her hand.”
Spys, information gatherers, and saboteurs. Lilin are descended from one of Hell’s original queens, known as Lilith. While most Devils do not like the Lilin, no one denies their usefulness.
Domination Devil (Gladiatrix)
“Clad in spiked black armor, this female humanoid’s face is covered by a scowling mask. Only her eyes are visible beneath the black metal. Her muscles are taut as she whirls around a dire flail with dangerously exquisite grace.”
Female devils who are devotees to the Lady of Pain. Gladiatrix are warriors without peer, and they despise weakness.
Vengeance Devil (Salikotal)
“On lean limbs the color of spilt blood creeps a being of sinister grace. Eyes like embers and a sneer full of needle-thin teeth gleam from an unmistakably fiendish visage. A pair of crimson wings sprout from the back of the hairless humanoid form, fluttering silently like an assassin’s cloak, while in one hand it clutches the twisted, dagger-like horn of some infernal terror.”
The Assassin’s of Hell. They are employed by the Lords of the Nine Hells to hunt down targets all over the planes. They are experts of stealth assassination, gliding like inky shadows over water.
Sire Devil (Patraavex)
“This fiend is a horrendous amalgamation of snapping claws and writhing tendrils with a disgusting fanged mouth running vertically across its torso.”
These creatures are shape changers by nature. They work to insinuate themselves into human society and have children, who are almost universally born as a Tiefling.
Tormentor Devil (Tormentor of Souls)
“This reddish-gray scaled humanoid stands taller than a human. Its hands are clawed and its feet cloven. Oversized fangs jut from its upper jaw and drip foul-smelling saliva. Small horns protrude from just above its eyes, curving backwards. Its head and body are hairless and a small curving tail trails behind it. It wields a battleaxe and carries a wickedly-barbed net slung across its back.”
Like the Gaav and Magaav, Tormentor Devils scour the highest level in the Nine Hells to find wayward souls. They often also catch adventurers who may have accidentally stumbled into the evil plane.
Warmonger Devil (Levaloch)
“Armored like an infernal knight upon some monstrous steed, this fiend of iron and nails scuttles upon six heavy, bladed, beetle-like legs. Its body seems to be nothing more than plates upon hulking plates of dark metal, each pierced through with gleaming spikes studded with the gruesome trophies of past massacres. In one clawed gauntlet it grips a long, twisted trident, while in the other it readies a thick net woven with fiendish barbs.”
Devils fashioned from hellish steel and fleshy warriors, Levalochs are elite warriors on the field of Battle. They are elite armies unto themselves.
Blood Reaver Devil (Garugin)
“This tall reddish-bronze colored humanoid has leathery flesh and gleaming, gold eyes. Its hands end in blood-stained claws, and a long snake-like and forked tail trails behind it. The smell of fresh blood hangs in the air. It wields a wicked dual-headed flail.”
Hell’s “Security Force,” these Devils stalk the Nine Hells looking for Adventurers who have strayed into the evil plane.
Drowning Devil (Sarglagon)
“Frail, fin-like wings erupt from the back of this serpentine creature, whose head resembles that of a ram-horned, four-eyed fish, and whose muscular arms end in masses of writhing tentacles like fists made of sea anemones.”
These Devils prowl Hell’s waterways, dragging foolish souls to drown in the Mires of the Fifth level of Hell: Stygia. They collect secrets and knowledge there, extracting what they can from their victims.
“This tall, bronze-complexioned man is abnormally long-limbed and clad in armor of stained and battered coins. His wiry frame is festooned with mismatched bracelets, rings, and necklaces, each gaudier than the last. The easy smile on his face is cold with envy.”
Devils who serve the wealthiest of Hell’s Princes and Archdevils, Gilded Devils are rarely seen outside of the Nine Hells. When dealing with Mortals, they often tempt with riches and wealth.
Interrogator Devil (Amaimon)
“This massive creature stands nearly 10 feet tall and looks like a bloated, squat humanoid with scarlet flesh. It has a long curved and forked tail, clawed hands and feet, and a round, squashed head with two small horns just above its sapphire-colored eyes.”
Interrogator Devils are the inquisitors and torturers of Hell, extracting knowledge by pain from the various souls that come their way.
The Furies (Erinyes)
“Some calamity has befallen this angelic warrior. Wings stained black shear the air as her merciless eyes search for a target.”
Mockery of what they once were, the Erinyes are Angels fallen under Hell’s influence. Used as the shock troops by Hell’s powerful Princes, they are merciless executioners.
Bone Devil (Osyluth)
“Merging the most horrifying features of carrion-fed insect and withered cadaver, this bony devil moves in unsettling lurches.”
Inquisitors and whips of Hell’s Legions, Bone Devils delight in torturing mortals and other devils at the same time.
Faceless Devils are another set of shapechangers and assassins at the beck and call of the Princes of Hell.
“Brutalis devils are enormous and sinewy, standing around ten feet tall and weighing tons. Their sandpaper hides are a dull golden, and their shoulders and the crown of their heads are crested with horns. They carry enormous swords of cruel flame. Brutalis devils carry themselves like soldiers, standing at a menacing parade rest most of the time, except when fighting or orating. They have deep, somber voices. A quirk of infernal magic means that their voice always sounds exactly like the father of whoever hears them.”
Brutalis Devils are the brutal enforcer of the Law of Hell. Some prowl the streets of Hell’s cities, while others go on to serve rulers in courts throughout the Evil Plane.
Cabal Devil (Uniila)
“The curves of a shapely maiden define the outline of a mysterious figure wrapped in mist and strips of ancient robes. From beneath the rune-embroidered tatters stretch four, corpse-pale arms, each bearing either a blade or some mysterious arcane device. Hidden within the cowl of its hood shimmer the faintest outlines of a veiled face and a pair of eyes flickering with barely restrained energy.”
Uniila Devils are entities who tempt mortals like any other devil. Instead of physical prowess, delights, or material wealth, they offer bargains for magical power.
Contract Devil (Phistophilus)
“With rust-colored skin and a jutting crown of ridge-like horns, this muscular devil is draped in lengthy contracts.”
The Scribes of Hell, Contract devils serve the Dark God Asmodeus, keeping records of all the deals the Devils tempt mortals with.
Barbed Devil (Hamatula)
“From the tip of its lashing tail to the serrated features of its fang-filled visage, this fiery-eyed sentinel bristles with barbs.”
The Jailors of Hell, Hamatula keep the damned souls of mortals locked away in their proper place and enforce Hell’s many laws.
Castigas Devil (Automata)
“A nightmare wrapped in chains, built of cutting cogs and whirring gears, this monstrosity seeps pure malice.”
Devils who monitor others for any sign of weakness. Castigas Devils are often in charge of Hell’s Infernal Factories and Forges.
Executioner Evil (Munagola)
“Corded muscles ripple under this massive devil’s red skin as her black wings beat overhead and her black eyes smolder like coals.”
The Munagola are an experiment by the Queen of the Erinyes to create even better warriors for Hell’s armies. They are rarely seen even in Hell because of their creation process.
Flayer Devil (Marzach)
“This hulking brute has leathery, crimson skin, and a large mouth filled with razor-sharp teeth. Large, round horns protrude from the sides of its head. Its hands and feet end in claws, and its eyes are slitted and bronze.”
Another Hunter type Devil, these monsters hunt down incursions into the deepest parts of Hell. They serve Asmodeus directly as his personal hunters.
Heresy Devil (Ayngavhaul)
“Seemingly fused with a monstrous throne of iron skulls, this impossibly corpulent being floats several feet off the ground. Trappings cut in mockery of holy vestments do little to cover the thing’s pallid, leaking rolls of blister-pocked girth. Worthless, club-like hands waggle like maggots, directing a cloud of weathered scrolls and blasphemous tomes that orbit its bulk. Barely distinguishable amid its mound of chins squints a pair of glassy black eyes, riding above a disproportionately wide mouth curled into a perpetually lecherous grin.”
Devils that create despair and terror in the hearts of mortals who are doubting their faith. They specialize in creating evil cults to gain influence in established religions.
Ice Devil (Gelugon)
“A pair of frozen, multifaceted eyes coldly judge all before this towering, insectile monstrosity.”
Elevated Mortal Souls whose cold, calculating, and evil hearts manifest their ice exterior.
Judgement Devil (Ashmede)
“Huge black bat wings extend from the back of this powerful serpentine humanoid. In its claws hands it swings a vicious-looking scythe.”
The judges and enforcers of Asmodeus’s Will in the depths of the Nine Hells.
Handmaiden Devil (Gylou)
“Twin tentacles stretch from the crown of this feminine fiend’s head, while her lower body blooms in a gown of writhing tendrils.”
The Attendants of the Powerful Queens of Hell, they have affinity for Erinyes as followers.
Pig-Faced Devil (Chort)
“Small horns crown the head of this pig-faced devil. Quick and canny, the creature stands on shaggy goat legs and holds a flaming polearm in its clawed hands. It bears a wicked gleam in its black eyes.”
Devils that specialize in Fear and Intimidation. They delight in scaring mortals and offer bloody revenge on those who have wronged others.
Belier Devil (Bdellavritra)
“This amphisbaenic monstrosity has the body of a slug with a leech’s mouth at one end and a knot of three human heads at the other.”
Masterminds and Planners, Belier Devils scheme against everyone and everything, they like to possess mortals and use them in their long term plans.
Devourer Devil (Ghaddar)
“This massive creature stands almost three times as tall as a human and has the head of a donkey. It shuffles with a hunched gait as it moves. Large downward-curving horns protrude from its head. Its body is covered with blackish hair. Its feet are splayed and its eyes are stark white with hollow black pupils.”
Devourer Devils roam the levels of hell, consuming all in their path. They eat mortals, devils, and even other beings.
Horned Devil (Cornugon)
“Bristling with terrible spines and a crown of deadly horns, this leering winged terror wields a whirling barbed chain.”
Hell’s High Commanders. They lead whole Regiments of Hell’s Armies in battle. They are Elite Warriors created from the most ruthless of mortal souls.
“Hidden within a cloak of darkness, two large, radiant, angelic wings sprout from this creature’s back while skeletal hands wield a translucent, skull-decorated scythe.”
Fallen Angels who are trapped by their own poor decisions to side with the forces of Hell in centuries past. They are Obsessed with punishing evil mortals.
Apostate Devil (Deimavigga)
“Armored in the ceremonial garb of some grim knight, this figure stands unnaturally still, though the intricate metalwork patterns of its sculpted mantle writhe and shift as if alive. Claws the length of longswords extend from its armored fingers in razor-sharp fans, and no head or helm rests upon its ironclad shoulders. Instead, there hovers only a plain mask, an unnatural facade devoid of all empathy, emotion, or mercy.”
These Devils are chiefly concerned with turning mortals away from the worship of the Gods. They offer “Freedom” in the service of Hell.
Nemesis Devil (Advodaza)
“This ancient monstrosity has the torso of a massively muscled giant, scaly wings, and the lower half of a four-legged, clawed beast.”
Nemesis Devils are ancient Devils who once masqueraded as dark gods and vengeful spirits on the Material Plane. They seek nothing more than the worship of Mortals.
Deathleech Horned Devil
“This horrifying horned denizen Hell would be terrifying enough, but there is a strange, unnerving aura about its countenance—unusual for even its kind—and a faint chill in the air seems to surround it.”
Greater Versions of the Cornugon, Deathleech Horned Devils are amongst the most powerful combatants on Hell’s battlefields.
Immolation Devil (Puragaus)
“Ash and embers encrust the smoldering humanoid frame of this imperious, dragon-winged devil.”
Puragaus are the generals of Hell, second only to the Pit Fiends. They are beings of Flame and Fury, lacking the subtlety of the Pit Fiends, but no less cunning.
“A pair of gigantic, flame-seared wings and eyes smoldering like embers give this towering devil a truly horrific appearance.”
The big Fiends themselves. These are the top tier monsters in the planes of Hell. They are brutal conquerors, who summon armies of lesser devils and like to invade other planes and take what they feel is rightfully theirs.
At the top of the Devil Hierarchy are the Archdevils. Each of them hold sway over a layer in the Nine Hells. These threats are CR 20+ and meant mostly as background villains for your campaigns.
They rarely ever interact with the material plane, and are often more caught up scheming against each other.
Pathfinder 2nd Edition
Pathfinder 2nd Edition Devils are very similar to the devils from 1e. They have the same rigid Hierarchy as the Devils from 1e, but there are (currently) fewer variations. Below they are listed with their Hazard Level.
While it is somewhat difficult to compare them mechanically, rather than just rewrite the entry for each devil in question, instead I will note if there are major differences in how they are presented and roleplayed.
Lemure Creature 0
Lemures are changed very little, but more powerful Devils can cause them to combine into superior versions of them.
Imp Creature 1
Imps are unchanged, but now have shapeshifting powers to keep them hidden in the Material Plane.
Zebub Creature 3
These Devils are unchanged from their 1e incarnation.
Hellbound Attorney Creature 4
Mortal Thralls to Contract Devils, these creatures are beings who make deals with Contract Devils to improve their Legal abilities on the Material Plane.
Bearded Devil (Barbazu) Creature 5
Bearded Devils are relatively unchanged, but one difference being they are more focused on murder and mayhem on the Material Plane.
Warmonger Devil (Levaloch) Creature 7
Diabolical Hunters serving in Hell’s Armies.
Fury Devil (Erinys) Creature 8
Erinys are not always fallen angels, but the earliest ones were. Now they are focused on Vengeance and enforcing ironic punishments on mortal souls.
Drowning Devil (Sarglagon) Creature 8
Sarglagon’s are unchanged from Pathfinder 1e, but they also have a tendency to “adopt” mortals who they find interesting and become evil guardians of them.
Bone Devil (Osyluth) Creature 9
Bone Devils seek out and hunt for Heresy among Devil and Mortal alike. They are Hell’s most terrifying inquisitors.
Contract Devil (Phistopilus) Creature 10
Bureaucrats, Scribes, and clerks to the Archdevils of Hell, Contract Devils keep records of the deals made with mortals as well as Hell’s myriad laws.
Barbed Devil (Hamatula) Creature 11
Barbed Devils are designed as guardians of the Vault of Hell. They are the bane of foolish treasure hunters who seek to steal from the Infernal Vaults.
Executioner Devil (Munagola) Creature 11
Munagola are the Elites of the Infernal Armies. They are brutal combatants who live for combat. They lack the finesse of Erinys, preferring brute force.
Ice Devil (Gelugon) Creature 13
Insectile Devils who use their cunning and intellect to gain the upper hand. They are the Devil Strategists of Hell.
Handmaiden Devil (Gylon) Creature 14
Gylon’s are diplomats and deceivers, serving in mortal and hellish courts all over the planes. They are known manipulators, but are very subtle in their dealings.
Horned Devil (Cornugon) Creature 16
The Commanders of the Infernal Armies of the Nine Hells, Horned Devils are powerful Battlefield commanders. They are forged in hell fire from the souls of renowned and bloodthirsty warriors.
Apostate Devil (Deimavigga) Creature 17
Apostate Devils seek to turn mortals against each other, using subtle long term plans to turn friend against friend.
Tyrant Devil (Pit Fiend) Creature 20
Pit Fiends are very little changed from editions. These beings are more extensions of the will of the Archdevils of the Nine Hells.
Gamemastering the Diabolic
Devils and the Nine Hells are an awesomely powerful resource for Gamemasters to use. Whole campaigns can be built around just resisting (or assisting) their machinations. They are deep with a great deal of lore.
However GMs can sometimes get overwhelmed by how exactly to use them. We can help though!
Role Playing Devils
It almost sounds foolish to say this, but one must keep in mind that Devils are in fact Lawful Evil. They are beings of centuries-old Malice and Hatred given form and shape. Almost every denizen of the Nine Hells is there for a reason.
They are either condemned souls or fallen celestials who now call a plane of fire, ice, and poison their home. That should go a long way to inform you on how exactly they interact with reality around them.
This does not go to say they are universally slavering beasts out for mortal blood. Even the lowest level of Devil (Lemures and Imps) have some cunning and understanding. Each and every Lemure was once a damned soul that managed to IMPRESS one of his captures enough to reconsecrate them as a Devil.
Lower level devils may kill on sight, but more often than not, if a Devil is higher up on the totem pole, they might just try to strike a deal. Devils WANT evil souls to take to Hell, and they are functionally immortal when it comes to aging.
They have the time to take things slow. A Devil’s plans could take decades or even centuries to come to fruition.
If a character does strike a bargain, it is worth knowing that Devils are very much Lawful creatures. They will stick to the letter of a deal from start to finish.
Of course, nothing is stopping them from bending the truth, but they rarely fully lie (Lying is an evil act, not a chaotic act). They will always hold up their end of the bargain, especially if it has some unintended consequences.
Devils in Combat
Devils are cunning, intelligent, and lawful.
Devils will plan ahead before combat. They are not horde fighters, and would much rather plan for eventualities rather than just jumping straight in. The militaries of Hell are regimented organizations, and that is going to come through in their small unit tactics.
Every action they take is going to be ordered and planned out, and there is rarely going to be room for being “creative” with battle plans.
They will also know their capabilities and use them often. Spell Like Abilities, immunities, and Damage Reductions are all going to be things these creatures actually bank on and know how to use to their advantage.
They will do the same with any weaknesses they might pick up on in their foes, capitalizing on any mistakes the players might make in the fight.
A Devil’s Place in the Campaign
Devils are a great addition to any possible campaign that has the potential to reach beyond the Material Plane. Hell is a major power on the Planar Scale, and if players start to have influence beyond the Material Plane, they will more than likely get picked up on the radar of some powerful Devil.
Use Devils as big villains.
Obviously, Lemures and Imps are not going to be much of a challenge over time, but beings like Phistopilus or Gylon would make great long term foils for the PCs, as they can have long term plans.
Once the PCs get past them, you can always up the ante with Pit Fiends as the real top of the line.
Most often though, Archdevils are not going to take much interest in a band of adventurers, as they have much BIGGER things to worry about. That is unless that band of adventurers is really good at defying an Archdevil and ruining ALL their plans.