Nightmare Fuel / Geist: The Sin-Eaters

Meet the Kerberoi.

• The mere presence of a Sin-Eater reinforces the surrounding ghosts whether they like it or not, effectively allowing them to manifest more easily; a Sin-Eater can single-handedly plague an area with ghost activity and apparitions just by being here. Which can become pretty bad if said ghosts are vengeful or malevolent...
  • The Hunter supplement Mortal Remains reveals Slashers are terrified by Sin-Eaters for this very reason; they don't expect their victims to come back for revenge, which is exactly what can happen when a Sin-Eater shows up and allows the pissed off ghosts of all the people they killed to come back as super-powered immaterial beings - to say nothing to the Sin-Eaters themselves having Resurrective Immortality. You read that right; the Bound are in-universe nightmare fuel for serial killers.
• The Wretched are sin-eaters that have become Meat Puppets for their geists, surrendering control to their geists some or all of the time. Some are blessedly unaware of what their bodies are doing, like La Diabla Blanca, whose geist merely possesses her in her sleep. Others are not so lucky, and must watch from inside their own heads, unable to do anything as their geist wears them like a skin suit.
• Good news: you can come back from death if you're ever killed! Bad news: someone else has to die in your place, and you get to experience how they die just as you come back to life. And yes, you are aware that it's your fault, and yes, the experience can drive you mad. Even if it doesn't screw you up, a bit more of your control over the geist crumbles every time... and your potential control withers.
  • You also have to take in account what this means for a Sin-Eater's enemies. Sure, for the Sin-Eater, dying too many times is a bad thing because it gradually makes him lose his control over his Geist... but that doesn't make it a good news for his opponents. A Bound who runs out of Synergy and becomes a Wretched won't actually become Deader than Dead, he will keep coming back while growing more and more insane, meaning he is unlikely to stop fighting. His opponents just can't hope to actually kill him, just delay him for around a night. And someone dies each time he comes back.
  • 2E changes this around, as it is now actually possible to kill a Sin-Eater for good with the right weaknesses or by having one run out of Synergy. Of course, this is little consolation, as there is no way to know how much Synergy they have left, and they can now raise it back up, meaning they no longer have any restriction for how long they will stay sane. As for the weakness, it isn't like Silver for Werewolves, sunlight for Vampires, or Cold Iron for Faeries, where you can just find a common Kryptonite Factor and use it against all of them; no: each individual Sin-Eater has completely different weaknesses. Meaning even if you're lucky once and manage to kill one, you'll find out the same trick doesn't work on the next you meet.
• Some of the powers granted to Sin-Eaters by the various Keys and Manifestations are truly horrifying:
  • The Stigmata Key grants power over blood and ghosts. It makes its user bleed, it makes a sin-eater's enemies bleed, it makes the walls bleed... oh, and it can be used to command ghosts, who can in turn possess people.
    • When combined with the Caul, it can also be used to detach your arm and control it remotely. Or similarly control a pool of your own blood remotely and see through it. Or spawn an Homunculus from your very blood, essentially making a blood golem. Sweet dreams.
  • The Phantasmal Caul lets a sin-eater literally become someone's worst nightmare made flesh. Given the image that accompanies this power in the core book, it's not surprising that merely looking upon a sin-eater using this power is a good way to go insane.
  • Phantamsal Marionette allows the user to form a plasm-copy of their Geist's body and plant their mind inside of it. Higher uses allow the user to increase the power of this body, making it a more effective method of reverse-possession - the player also gains bonuses to their Intimidation skill, and considering what a Geist can look like...well, it's quite disturbing to think of.
  • The Tear-Stained Rage allows you to fill your opponent's lungs with water, drowning them on the spot.
  • The Pyre-Flame Rage allows you to set people on ghostly fire. At lower levels, the flames are purely psychosomatic, meaning they don't truly harm (though they still are painful), but at higher levels, they become quite real and often burn the victim entirely to ash.
  • 2E raises it to a whole new level. Among others, the Caul has been made into full-blown Lovecraftian Superpower and can now be used to turn you into basically John Carpenter's the Thing, allowing you to grow fangs, claws or additional limbs, reshape the skin of your body into wings, or devour someone to gain the ability to shapeshift into them.
• Most Ceremonies practiced by Sin-Eaters are used to help ghosts, communicate with them and move to the afterlife. Then, you got "Quicken the Dead", which allows you to trap them in corpses and make them obey you, essentially creating yourself a personal group of zombies.
  • In general, Ceremonies can have pretty fucked up effects when in the wrong hands. Book of the Dead's opening fiction features a Yandere Sin-Eater who kills his ex in the Underworld, slays her Geist, then tries to forcefully bind her ghost to an Anchor he created so he can bring her back on Earth, have her possess a mortal woman and keep her forever close to him.
• Fetters are mementos that are powered by ghosts trapped within them. They are still quite conscious, but live only as tools for sin-eaters that want to make use of their numina. Sometimes it's a fitting punishment (like the movie camera holding a Snuff Film maker, the rifle holding a mass kidnapper, the spray can holding a ghost who never got the message about Disproportionate Retribution...), but many Sin-Eaters don't care about whether the ghost deserves it.
  • Soulsteel objects are quite handy, with generally good equipment bonuses and the ability to be used anywhere in the Underworld. Unfortunately, soulsteel is made of exactly what it sounds like, and the implication is that they are still quite conscious in their current condition. That said, some ghosts are soulforged willingly, believing that they could be more useful in their new form.
• Abmortals are humans who found a way to gain immortality, usually through truly horrifying means, such as killing children or sucking life from other people. The sample Abmortal provided by the book is a soulless exorcist who keeps himself living by eating ghosts, and actively makes sure people spending enough time around him will die so he can eat them. But worse than that is, they are even harder to kill than any playable supernatural in the game: aside from a very specific Achilles' Heel unique to each of them, they just cannot die, period. You could cut them to pieces, burn them and reduce their remains to dust, and they would still eventually regenerate.
• Kerberoi are ancient death spirits that govern the Dead Dominions, enforcing the Blue-and-Orange Morality of the Old Laws. They're usually very powerful, very old, and very unforgiving of anyone who breaks the laws in their Realm. They also usually have no resemblance to any living thing, and often have a peculiar agenda of their own.
  • In the Imperial Mysteries supplement for Mage: The Awakening it's mentioned that Archmages usually avoid the Underworld because while they can defeat lesser Kerberoi, the ones who rule the deepest parts of the Underworld are at least as powerful as they are. That implies that being equal to transhuman gods who can alter reality any way they want limited only by the difficulty in acquiring the Quintessence that powers Imperial Spells is the minimum power wielded by the Death Lords.
• The Underworld itself. Best-described as an Eldritch Location version of Catacombs, this never-ending, underground-like world is where ghosts go when they lose all their Anchors, yet are unable to go to rest due to still having Unfinished Business. Unlike in the physical world however, this place actually allows them to evolve and grow in power, meaning ghosts and shades in this place will be much more powerful and intelligent, and all the more dangerous if they are malevolent or insane. Other inhabitants include Geists who still have yet to find a host and Kerberoi, some places are just plain bizarre, enough to cause a Sin-Eater to lose his mind if she isn't careful, and have strange, undesirable side effects. Oh, and if you spend too many night inside and then get killed, don't count on your Geist to bring you back; you will be stuck here until someone else comes to rescue you.
  • Book of the Dead reveals more details about the Underworld; among other things, it turns out ghosts inside it are subjects to a form of "gravity" that drags them deeper as they grow in age. Meaning as you get deeper in this place, ghost get older, more insane, more powerful and more dangerous, while the area itself becomes more and more bizarre. Keep in mind that the Autochtonous Depths (the highest level after the Avernian Gates themselves, which are in our world) cover ghosts who are roughly a century years old or less. The ones below are even older than that, and there are at least two more levels confirmed (the Lower Mysteries and the Dead Dominions).
  • 2E makes it worse; the Underworld now actively parasitizes the ghosts stuck in there, to the point where Dead Dominions actively themed after Hell still have immigrant spectres-after all, the Kerberoi aren't draining your Essence simply by you living there.
  • The Dead Dominions also are separated from each others by all kind of supernatural rivers. Some of them are harmless enough, but others include such nice sights as a river of blood, or a swarm of scorpions.
• Avernian Gates, which basically are portals to the Underworld. Now the idea of portals that could open at any moment to lure you into the realm of the dead or unleash insane centuries-old ghosts is pretty scary in itself, but then Book of the Dead provides us with a few sample famous Gates, which show us how truly dangerous these places can be:
  • The Grand Rosetau, an Avernian Gate in the pyramid of Giza, can only be properly opened by performing a full-fledged mummification ceremony on a freshly dead corpse and burning the resulting mummy's heart. This also has the unfortunate side effect of reanimating said mummy as a very aggressive zombie who will attack you on the spot.
  • Another has the ability to attract Death Seekers to then warp them into vicious, ravenous shades who then wander around next to it. Unfortunately, that Gate happens to be in the Aokigahara Forest, a place famous in Japan as a spot regularly used for suicides.
  • The Hagia Sophia has one hidden below it, where lay many treasures and powerful artifacts; unfortunately, it also happens to be the lair of a gigantic, arachnid monster, who uses all these treasures as baits to lure Sin-Eaters to it so it can devour their Geists.
• 2E gives us the Reapers (no relation to the Archetype of the same name in 1E), ghosts who support the Status Quo of the Underworld under the misguided belief it works. In their natural state, they are just regular ghosts with no special ability for their kind... until they put on their Death Masks, which make them go One-Winged Angel and turn them into nightmarish beings on part with the Kerberoi. They have the ability to capture ghosts and forcefully drag them to the Underworld- and when that doesn't work out, they can assemble to drag entire city blocks, living and dead alike, into the Underworld. Civilizations have disappeared because they decided it was the best way to handle a troublesome ghost situation. And since they look like regular ghosts without their mask, they could be any ghost you ever met.