"I'll hurt them, Erin. I'll grab ten at random and tear their skin off. This is paradise compared to what I've done in other worlds...Ten, then a hundred, then a thousand. The children alone are in very, very high numbers. I'll peel them like fresh little grapes and make you hear every scream."
—Nyarlathotep, to Erin Hasegawa, Nights In Lonesome Arkham
Entries in each group are in chronological order.
In the Castle of the Night
- Count Nicolai Gabriel von Krolock, the Big Bad, is a Strigoi Mort vampire who seeks to spread terror and murder across the world. The youngest of the von Krolock family, Nicolai sought the ownership of Castle Krolock from his parents, murdering his brother Serghei's entire bloodline to do so. During his time in the castle, he tortured countless numbers of humans and fay alike for their blood, to the point where he caused several races to go extinct; spread a monster-turning plague that wiped out the city of Wisborg; slaughtered numerous villages across Transylvania for sport; and formed a cult who would sacrifice both adults and newborns to the dark lords in exchange for power. Seemingly dead, von Krolock implants his soul into his castle, planning to completely resurrect his physical self, using Serghei's last descendant Stefan as an immortal anchor to the physical realm and hiding him under his bed, preventing him from sunlight, food, and water. Using his spiritual powers, von Krolock has Frederick Hughes lure countless people to his castle, where von Krolock kills them in their sleep, implanting their souls into Pricolici wolves to serve as his attack dogs. When Hardestadt Delac arrives to stop him in the middle of a tour, von Krolock eviscerates most of the tourists, kills Frederick, and drains half of the Barovian villagers' blood to regain his energy.
- The Pijavica, actually the mother of the mute orphan Aleksandar, is the entity whose murder of Father Collins and attempt to bring Aleksandar back into her clutches sets up the plot. The Pijavica murders one of the nuns of the Maryland orphanage Aleksandar lives in to pose as her, slaughtering another when she reveals her true identity and attempting to massacre all of the other children and nuns there to get at her prey. The vilest revelation concerning Aleksandar's "Majika" was her constant incestuous attentions on Aleksandar in life—dooming her husband to hang when she was exposed and executed—seeking to rape Aleksandar one more time before murdering him as well.
- Y'golonac is the god of depravity and a cruel Great Old One with a love of violating others. Fully capable of understanding human thought and emotion, Y'golonac lures a depressed Leon Duvalier to his cult in order to eat away at his soul as he possesses him. Using Duvalier's body, he rapes, murders, and eats countless people while forcing his daughter Monica to watch, while also making her believe herself to be Duvalier's deceased wife Rachel in order to rape her himself. With the corpses, he keeps their heads in jars to scare Monica for fun. Luring Hardestadt Delac to his hideout in order to eat him, he later tries to make him say his name in order to break free from his prison and turn North America into his playground of chaos and violation. When Hardestadt refuses, he taunts him with the fact that Eliza had been raped by her husband, all while savoring his anger. As he departs, he teases Hardestadt that he might have been raped himself. A putrid, disgusting sadist, Y'golonac truly earns his nickname of "the Defiler".
- Rich Jacobs, the Big Bad of Girls on Film and the illegitimate son of Wallace Malcolm Hargrove, is a young vampire who figures that having the wealth and resources of his father means he can excuse being as vile as he can possibly be. Operating with no regard of the standards of his own kind, Jacobs sets up a snuff porn ring where hundreds of women are kidnapped by the criminals he's turned for the purpose of raping, torturing, and murdering them within the confines of one of his father's prisons, selling the films on the dark web for a profit and disposing of the bodies by feeding them to starved ghouls. Kicking off the plot by kidnapping a woman named Emma West, Jacobs turns her into a vampire and uses her for his "special" films by having her tortured and maimed by his men for countless days on end, a fate he's already bestowed on several other unlucky women. When the supernatural investigator Hardestadt Delac invades his operation, Jacobs captures him and forces him to endure physical and psychological torture for days on end for the glee of breaking him, while intending to finish him by letting the blood-starved vampire women tear him to shreds before Jacobs personally finishes him. When resurrected by Nyarlathotep in Nights In Lonesome Arkham, Jacobs sells out all humanity to destruction and kills thousands in service to his new master. Reviled by even his own kind, Jacobs is little else than a swaggering, entitled brat and a blood-hungry sadist underneath his weak facade of charisma and control.
- The aforementioned Wallace Malcolm Hargrove is the benefactor and father of Rich Jacobs and his horrific snuff porn films. Having taken Jacobs as his son after his own numerous sexual assaults and rapes led to the boy being born, Hargrove eventually saved the boy from a lethal sickness by turning him into a vampire. When an adult Jacobs offered his father the chance to participate in snuff films, Hargrove leapt at the chance, not only because he thought Jacobs would turn him into a vampire as well, but also simply because he enjoyed the thought of sending countless women to be brutally raped and tortured to death on films which he could later watch. In his final moments, Hargrove proclaims he feels no regret for having handed dozens of women at a time over to Jacobs, and truthfully doesn't care about his son except as a an object for his "legacy" and a means to immortality.
- Nyarlathotep himself is an all-too human monster distinguished from the other Outer Gods by his sadism and ambition. Once the nameless emissary of the Outer Gods who went from world to world to drive entire civilizations to madness before offering them up to be devoured by Azathoth, Nyarlathotep was given hope of a more meaningful existence by the angel Aleviel—before instantly reneging on that once she was cast down and vowing to annihilate the world she desired to protect out of spite. During his time on Earth, Nyarlathotep drives the entire city of Thinis to murderous, chaotic insanity, driving the populace to slaughter the city's children and restoring the sanity of the surviving populace their solely to bask in their suffering and horror; slaughters hundreds of thousands across the world, some merely as distractions; rises up the Great Old One Ithaqua in an effort to doom the planet to its deathly cold; keeps the populace of entire towns frozen in eternal agony as trophies of his previous conquests; and, at the end, reveals his intent to devour the other Outer Gods and come astride the rest of creation, devouring all in his way and keeping whatever is left to torment forevermore. With whatever decency Aleviel managed to awaken in him thoroughly trampled in the present day, Nyarlathotep is, at the end, nothing more than a wicked, spiteful, and endlessly sadistic entity thoroughly worthy of the moniker of the "Crawling Chaos".
- Siegfried Gunmarsohn is a brutal, red-furred werewolf who terrorized Soissons, Gévaudan, Chalons, and countless other areas with a slew of victims—especially children—to his name. Concerned only with his own notion of pure-blooded werewolves and seeking to put all humanity under his claw, Siegfried murdered his own mother, brother, and sister in succession over a course of centuries before seemingly meeting his end at the hands of Hardestadt Delac. Siegfried gave himself over to Ithaqua at the prospect of vengeance, resurfacing decades later as the leader of a town called Pine Creek, using his position to select dozens of innocent people from the village as fodder for his hunts and as sacrifices to Ithaqua, and handing over more of them for vivisection and experimentation at the hands of Sieglinde Nomura. Uncaring even to the deaths of his own children—which he's bred solely as Cannon Fodder for centuries—Siegfried plans to raise up Ithaqua and freeze over the entire world, ruling over the remnants of humanity to cull and hunt them as his own leisure forever.
- The aforementioned Sieglinde Nomura is Siegfried's daughter and a Mad Scientist who takes pleasure in experimenting on innocent people. After Siegfried was defeated by Hardestadt Delac several years in the past, Nomura helped nurse him back to health, and later assisted him in his schemes to eradicate humanity. Using a serum she invented, Nomura experimented on hundreds of thousands of humans and werewolves alike in hopes of creating a horde of werewolves loyal to only Siegfried, or destroying their minds so they'll be easier to control. Those who perished were merely disposed of or eaten, and records of how long they lasted were recorded in various notebooks. Whenever Nomura isn't trying to perfect her serum, she's vivisecting innocent humans and slowly eating parts of their body alongside her father—sometimes while they're still alive—or torturing humans she paralyzed just for the thrill of it. After Hardestadt and Erin Hasegawa are captured and Nomura finds out Erin escaped, Nomura willingly allows her to try and run away, all so she can take pleasure in hunting her down like a predator.
- Yamada, aka the Yamata no Orochi/Orochimaru himself, is a sadistic serpentine scientist working for Apophis. Once a mortal sage, Yamada made a deal with the Great Old One Serpent Father Yig to become a destructive serpent Yokai. Supposedly defeated by Susanoo, Yamada survived thanks to the power of Yig, and was later taken in by Apophis because of his cruel reputation. Working with Apophis to replace the afterlife with being eaten by Apophis, Yamada hopes to have the entire Teraverse serve as his own personal laboratory, hoping to experiment on countless humans and Fae. To feed Apophis, he infects countless planets with venom and offers the inhabitants a false cure that causes them to go crazy and kill everyone, with Yamada feeding their souls to Apophis, and using others to create agonized warriors who serve his every command. Seeking more power, Yamada has Yig captured and painfully experimented on as he extracts his power into Apophis, while also using his energies to create the drug Cobra, which Yamada hands it to countless humans who end up poisoned, their souls easier to extract. Tasked by Apophis to feed him the souls of gods, Yamada has countless sun gods captured and tortured to death in order to create more Cobra. Yamada later has serpent Jormungandr cause natural disasters to sell Cobra as an aid, reveals to Kaliya that he killed his wife and son before ripping his heart out; kills Susanoo with his bare hands; poisons millions while attempting to turn the world into ash; and attempts to destroy Valhalla and Hell itself before his death.
- Helen Valentine, the head of the commune of Bacio, Italy, defines love only as much as it can hurt others. Having made an Eldritch Abomination known as "Il Padre" her husband several centuries ago, Helen produces children to fill Bacio's ranks while savaging the minds of visitors in Bacio to turn them into dark shells of themselves, even her own children who she uses to participate in horrific and bloody orgies where the citizens of Bacio tear each other apart every Valentine's Day. At one point, in a fit of excitement, Helen even bites out the throat of one of her infants, gleefully planning to expand the darkness of Bacio worldwide.
- "The Consultant", real name Lucia, is a member of the ancient, godlike race of Daydreamers who serves the imprisoned being, Lord Draynak. Having been exiled by her own people for her cruelty and wickedness, Lucia allied with Draynak to use him as a way to get revenge. Seeking a child of the bloodline of the race of Seers, Lucia takes countless guises, manipulating endless bloodshed and pain so she can find a necessary host for Draynak. Using monsters from the other worlds to annihilate entire towns and villages, Lucia takes potential hosts and infests them with leechlike creatures in a horrific violation that inevitably results in their deaths. When she found a suitable host, a 13-year-old girl, Lucia murdered her, intending on double-crossing Draynak the entire time. Having found a suitable host in one hero Daniel's daughter Crystal, Lucia took great delight in agonizingly infecting her, murdering their friend Christian when he attempted to attack her. Later attempting to torture Crystal's sister to death, Lucia reveals she has always intended to annihilate all that lives as punishment for her humiliation, viewing everything below her as a toy to torture.
- "Vladik Cardinous" sought to expand his influence across the world by disguising himself as a human, kidnapping multiple animators and enslaving them to work on a specific piece of animation. Keeping the animators as slaves, Cardinous slowly mutated them into living monstrosities that were slaves to his will, using the film to corrupt the minds of those who saw it, especially children. When unsealed in modern times, Cardinous reveals the video will premiere over the world, allowing him to conquer all of humanity, with the survivors as his agonized servants forever.
The Lonely Dreams crossoverSangue Serenissima
- Eliphas Coyte is a wicked seeker of knowledge whose ambition led him to study The Dark Arts, which he used to make his own father brutally kill himself. Worshipping the eldritch "Ending Eye", Coyte brings it to his hometown, allowing it to devastatingly mutate his fellow villagers. Becoming fascinated by Eliza Cortly and the Seers, Coyte abandons the Eye, switching sides between various Dark Gods to play his own agenda and leaving them when it suited him, dragging people to be ravished by the "Defiler" and fathering eldritch spawn just to destroy them in inventive ways. Eventually coming to serve the "Masque", Coyte cannibalizes the brains of Seers to steal their connection to a mental web attached to the consciousness of all living things, aiming to devour the souls of everyone in Venice as part of his deal with Masque to ascend to godhood. Learning how this will annihilate large swaths of the Teraverse, Coyte remains apathetic as long as he gets to satisfy his thirst for knowledge. Creating minions by having their bodies warped by otherworldly powers and horrifically killing or mutating everyone in the Venetian Li Fonti manor, Coyte also consumes the minds of more Seers by boring into their skulls, getting "high" off the energies while their brains crumble to dust. Kidnapping the young Julio, a friend of Eliza's, Coyte threatens him to draw Eliza to his manor, then kills the boy anyways before she arrives, keeping his head to mock her over his death. Planning to kill Eliza when she finishes her purpose in his plan, Coyte misses no chance to show just how non-existent other human beings are to him in the name of his own pursuit of knowledge and power.