Xanthous

The human race will disappear. Other races in turn will appear and disappear. The skies will be glacial and empty, traversed by the feeble light of half-dead stars. These too will disappear. Everything will disappear. And human actions are as free and as stripped of meaning as the unfettered movements of the elementary particles. Good, evil, morality, sentiment? Pure 'Victorian fictions.' All that exists is egotism.
-H.P. Lovecraft

Peace grants men the illusion of life.
Shackled by falsehoods, they yearn for love, unaware of its grand illusion.
Until, the curse touches their flesh.
We are bound by this yoke.
As true as the Dark that churns within men.
All men trust fully the illusion of life.
But is this so wrong?
A construction, a facade, and yet…
A world full of warmth and resplendence.
Young Hollow, are you intent on shattering the yoke, spoiling this wonderful falsehood?
-Lord Aldia.

There's this hypothesis going around that I like that the Jeremiah/Old Monk character is the Souls' series take on Robert Chambers' the Yellow King. 

First of all, I'll assume if you're reading this you're already familiar with the Usual Suspects list of people I'll be pulling most of the info from. I'm not putting any of this forward as original work beyond gathering and synthesizing stuff that's already there and seeing what comes out the other end. In the unlikely case that you aren't familiar:

HI!

The Painted World of Ariamis

Remember: everything was originally put here because it was a threat to the Gods, but that was a very long time ago.

Don't panic. It'll make sense later.

Dark Souls is a game, and also a meta-phenomenon that is also a game. Fiction about a cursed work of fiction that causes an irl curse. Like In the Mouth of Madness. Only real. Only not really, because that would be silly and impossible.

The lore gets pretty headfucky pretty quickly, and is Marvel Comics dense, except it's this weird tree root thing where only 10% of the actual story is above ground and you gotta kinda guess at the rest based on how the grass grows above it. You should play it if you haven't. It's innocuous. If not, here's a quick catch-up.

The next paragraph sounds crazy. I didn't invent the internet.

Besides Vaati, I also watch and recommend the EpicNameBro, Silver Mont, DaveControlLive, and TerraMantis YouTube channels, the Twin Humanities and Bonfireside Chat podcasts, the wikidot wiki-although I used the others, I just prefer their layout-and the Dark Souls Reddit.

Any other anything is probably from some that-related wiki page. I'll try to link it if not.

If you're unfamiliar, the "Yellow King" was originally an inferred character from a book of short horror stories called The King in Yellow by Robert Chambers (1895) and incorporated elements of, among other things, Ambrose Bierce's "An Inhabitant of Carcosa" (1891,) arguably the first definitive example of what is currently known as 'cosmic horror.' It's a fairly new thing because it kind of came about because of modern science. Like, when you consider the sheer number of unknown unknowns it's amazing anything survives. I mean, what did we do with uranium and shit when we dug it up before we worked out what electrons did? Probably assume it was a magical rock sent by the gods, make charms out of it, and fucking kill everything we touch for the next few years when a mysterious plague breaks out.

Then we got smarter and started writing things down and even reading them occasionally and all of a sudden we have machines. And sweatshops. Engines. The fields of cosmetology and surgery part ways. Printing press. Railroad. Telegraph. Mortars. Long guns. Trench wars. We, like Lovecraft's Outsider, saw ourselves in the mirror for the first time on a truly global scale.

Scale that up to a world with Large Hadron Colliders and Waste Isolation Pilot Plants, drone warfare, social media terrorism campaigns, global warming and phones where I couldn't even begin to tell you how they work. Satellites? It's satellites, right? Anyway,

Cosmic Horror, generally, means 'like Lovecraft,' although that's like saying science is 'about physics.' It's true in a horrifically oversimplified way, but it is most definitely a statement asking for a 'yeah, but.'

Here is a 6 minute clip explaining what cosmic horror is.

I seriously need to watch True Detective. I thought
it was just some formulaic cop drama bullshit.

A 'yellow king,' in the cosmic horror trope sense,

Jeremiah, Xanthous King

refers to both/either a cursed or forbidden 'Play' within a fictional narrative that revolves around a sinister, inhuman King; and a sinister, inhuman King responsible for the 'Play,' that he also somehow resides inside of. The Yellow King is almost always an abomination in the very fabric of reality disguised as a regular person, and will almost always include a direct meta-reference to a former yellow king as part of the lore surrounding the forbidden knowledge in the Play. “Xanthous,” for example, is an archaic word for yellow that I read, somewhere (lost the link,) was associated with disease and quarantine at the time it was in usage.

The Yellow King is a remarkable character archetype in that it appears to have evolved as a sort of combination of ongoing convergent evolution and author meta-game among genre writers over the course of the past just-over-a-century (being predated with a lot of obvious church influences, as well as the general horrendousness of much of the industrial-modern age,) with different authors and directors and artists giving their own spin or interpretation. While the King and the Play usually has a fairly straightforward Lament Configuration/Cenobite relationship the important central point is that the protagonist is basically Wile E. Coyote running off a cliff, holding up a 'Yikes' sign, and then falling into that hole Gandalf fought the Balrog in, landing in a part of the universe where planets and galaxies and gods are the same thing and physics is set to Cronenberg, where blind, pale things scream hosannas in the language of and tin and broken promises as they beat their misshapen skulls against stones in caverns beneath foul seas, and somewhere behind it all he knows, as he wakes in his dark bedroom, is, like, a 10-year-old British conjoined twin that's going to grow up to be the Antichrist and make it all happen and no one believes him so he eventually shoots himself in the head behind a dumpster on skid row three months later because the dreams are escaping into the waking world and the worms are everything and the worms are in you and the worms are you and the hole in the center of you isn't a drain sucking all peace and joy from the world, no, it's a pump, pumping the horror of the dream place in.

Additionally, the King's true name and nature are never revealed (or shouldn't be, Derleth,) though he/she/it is usually represented by fallen nobility and insinuated to be the herald/thrall/servant of some far more hideous  and incomprehensible evil (Chambers initially linked the King to Hastur the Unspeakable, another apparent invention of Ambrose's [possibly a play on 'pasture,' 'pastor,' 'Ishtar,' or similar,] with Lovecraft and others (Derleth) solidifying the link with the King being a sort of omnipotent herald or equivalent leading a secret cult of Hastur: an amorphous dark god identified both as an entity and a place and a tentacles).

The King in Yellow is a collection of short horror

The Tall Man, Phantasm films.

and fantastic fiction "named after a fictional play with the same title which recurs as a motif through some of the stories...[The play] induces despair or madness in those who read it."(WP)

The play is said to contain two acts, the first of which is seemingly, beyond being somewhat risque or unseemly, perfectly harmless. It's generally alluded that an actual performance of the Play (or public broadcast of the recording or whatever,) would open a gate to Hell Or Worse.

The first act, "banal" and "innocent," acts as a whirlpool, sucking the unsuspecting viewer/reader in, while the second act turns into the irresistible vortex where all and everything is destroyed in cold and howling darkness.

Sort of like playing Dark Souls for the first time inevitably leads people like me to writing a literal research paper about a minor side-quest NPC most people never notice--beyond the hat occasionally showing up in PvP--4 years later.

Some excerpts.

Cassilda's Song: 

Along the shore the cloud waves break,
The twin suns sink beneath the lake,
The shadows lengthen
In Carcosa.

Strange is the night where black stars rise,
And strange moons circle through the skies
But stranger still is
Lost Carcosa.

Songs that the Hyades shall sing,
Where flap the tatters of the King,
Must die unheard in
Dim Carcosa.

Song of my soul, my voice is dead;
Die thou, unsung, as tears unshed
Shall dry and die in
Lost Carcosa.

The Yellow Sign 

"Night fell and the hours dragged on, but still we murmured to each other of the King and the Pallid Mask, and midnight sounded from the misty spires in the fog-wrapped city. We spoke of Hastur and of Cassilda, while outside the fog rolled against the blank window-panes as the cloud waves roll and break on the shores of Hali."

The King in Yellow had a major influence on, among others, HP Lovecraft, who would work references to Chamber's work into the Cthulhu Mythos, just as Lovecraft's own "cursed play," the Necronomicon, began to embody the 'inescapable curse' theme of the trope.

Many other examples of the idea, to varying degrees and intentionality, have been explored in pretty much any form of media. Lovecraft, films like The Yellow Sign (2011,) our man Jeremiah, and HBO show True Detective (apparently,) all make oblique references to Chambers' book, while some, like the works of Sutter Kane in the film In the Mouth of Madness, the play Love's Labour's Won in the Doctor Who episode The Shakespeare Code, Jorge Luis Borges' eponymous Book of Sand, 1998 supernatural crime drama Fallen and even, arguably, fictional non-fiction like The Theory and Practice of Oligarchical Collectivism from Orwell's 1984; all dealt with the idea of seemingly innocuous 'plays' or nobles hiding monstrous evils that THEMSELVES appeared innocuous.

My personal favorite example of the yellow king

2002 U.S. Ring remake.

trope are the Ring films, particularly the 2002 Verbinski remake, based solely on the unsettlingness of the Play, with me personally having almost three heart attacks when my phone rang just as something started climbing out of the TV screen on the TV screen. While it doesn't seem to be a direct reference to the Chambers/ Lovecraft trope, the VHS tape functions perfectly as the Play and whatever Samara is makes the absolute best Yellow King yet captured on film.

Incidentally, it's another modern example of the idea, along with Miyazaki's Jeremiah, being ping-ponged between Eastern and Western cultures.

So, Xanthous King Jeremiah. Or his peculiar hat, rather. What we know about him in-game:

1. His red phantom invades at the top of the stairs leading from the Phalanx courtyard to the, uh, stake garden.

2. He uses chaos pyromancy, arts only taught by Izalith nobility.

3. He uses a notched whip, a torturer's weapon, not a warrior's weapon.

4. His armor has average to kinda bad stats, with interesting notes being poor fire defense and high magic defense.

5. His headwrap has 35 curse resistance, and is the only piece of the set to have curse resist.

6. He invades after you've poked around in the garden for a bit when you're in human form.

7. His corpse is found sitting on a bench past Crossbreed Priscilla.

8. He drops a lot of souls compared to his threat level.

9. Using the Dark Hand on him does not yield humanity.

10. His Garden has a very unpleasant theme...song.

Some further notes on the environment and enemies in what I'm calling Velka's Courtyard and Jeremiah's Garden.

The Phalanx enemies share a similar morphology to the cragspiders, in that they appear to be hollows fused into an asymmetrical lump, also they all have three spears broken off in them, giving them seven 'limbs.' They really don't want anyone getting close to that statue. They're weak to fire. There's no real way of telling if they serve Velka, Jeremiah, Priscilla, or some other being or purpose. The shields they carry, (which look like large, golden Target Shields,) are not the shields they drop, which are Leather Shields. Possibly this last was a time/budget issue. I doubt they were meant to drop Target Shields, as that would make even less sense for a Phalanx formation than leather, although leather would be plentiful...

The cut Shiva the Traitor side-quest culminated here, with a Lautrec-style invasion of Shiva and his bodyguard, presumably after they murdered you with the stolen Chaos Sword.

There are usually more than one hollow on a pike, seeming to imply that this place used to be a lot more crowded. Seriously, there are Bloodborne levels of graves and corpses in this area, even just above ground.

If the statue is of a named character it is most

Velka w/ child. Maybe.

likely Velka. Velka, Goddess of Sin and its punishment is also one of the two candidates for 'mother' of Priscilla, the other being Gwynevere. As Velka is closely tied to the Occult, crows, humans, and the Painted World I think the odds are that it's her baby. A weapon has to be upgraded through the Divine path to +5 before being upgraded to Occult at a blacksmith. Velka has some sort of relationship with Gwyndolin, as she oversees the Book of the Guilty and the Darkmoon Blades carry out the punishment. Also, Gwyndolin's covenant, and the Darkmoon Blade miracle, are leveled up using Souvenirs of Reprisal, which drop from the Crow People of the Painted World. It's said that the “Black-Haired Witch” Velka is a "rogue deity...versed in arts both new and old," and is considered to have a "great range of influence even as gods are concerned." Sin is said to be the act of "disrespecting the Gods of [one's] covenants." Her talisman scales off of Intelligence instead of Faith and her rapier does Dark/occult damage that scales off of Int., indicating which she views as the more valuable in her Pardoners. It's widely believed that the Crow jail-breaking all these undead out of the Asylum is sent by-or may even be-Velka, who may also have had the doll placed in your cell. It was followers of the Occult that attempted to steal power from Nito, indicating that she, as much as Pinwheel and the necromancers, may be the one responsible for Nito's weakened state. Pardoner Oswald's dialogue regarding Petrus implies that Velka has eyes in the lands of the Gravelord. According to the experts, the crow people were originally to be worshipers of Velka, warped by their devotion, and in-game they go fucking crazy if you touch Velka's stuff. Finally, attacking Priscilla counts as a sin.

As it fucking should.

The bloated hollows would seem to be more-or-less straight-up followers of Jeremiah, the bonewheels likewise serve Velka. As to what their relationship is to each other...they're both way harder to fight than they seem like they should be?

The snow rats cause Toxic which, unlike poison, pyromancers don't seem to mind much. They also seem terrified of anything human-shaped. 

This land is peaceful. 

Note: one bloated hollow seems to be really keen on hiding in a forgotten corner, staring at his hands. 

Its inhabitants kind.

With his big, toxic, curse-immune head.

I would refer you.

There's more than a passing possibility that, under the yellow bandage, is a creature like the one known as the Parasitic Wall Hugger, a fairly harmless but incredibly gross non-respawning enemy on the middle of a wall surrounded by the level that makes everybody choose the 'Master Key.' 

Because who's the Master? That's right. You are. You're the master of that elevator, champ.

My tinfoil conspiracy theory is that the original citizens of Izalith--a matriarchy--were actually insects that used hollows as either host vehicles for their mature phase (Queelaag, Jeremiah, Sunbro if you didn't kill the chaos bugs on the way to Izalith,) or as breeding pods for their larva (Eingyi, the egg-burdened, the infested enemies). Word of God is that the witches aren't human, despite some of them appearing as human (Quelana, unnamed sister outside of the Bed of Chaos, corpse near Ceaseless Discharge,) or partially human (Quelaag, the Fair Lady). The Undead Rapport pyromancy, attributed to Quelana, turns hostile undead into allies, and this 'relationship is part and parcel to the art of pyromancy.' I just wanted to jam that in because it's a bit of lore that seems fairly important to how pyromancy actually works.

The idea, if I'm not being crazy, was expanded by Miyazaki further in

'Izalith Citizen' concept art

Bloodborne with the Healing Church/the Choir standing in for Izalith and the Chaos Witches. The concepts of beasthood and insight serve a similar host/parasite dynamic as the insects and pyromancers do in Dark Souls. The evolution from hunter to wolfman to werewolf to silverwolf (who spawn vile maggot-type enemies later in the game,) seem to represent a similar progression as the one we see in the enemies descending from the Depths, through Blighttown and Quelaag's Domain, through to Izalith towards the Bed. There's even a similar class structure, with the Undead Burg locking the door to the Lower Undead Burg, UdB locking the door to the Depths, and the Depths locking the door to Blighttown with things getting progressively more demonic on the way down.

In the Souls universe we know that the First Flame gave rise to 4 different Lords: Nito-First of the Dead, the Witch of Izalith and her Daughters of Chaos, Gwyn the Lord of Sunlight, and the Furtive Pygmy (humans, rats, the Dark Soul).

Nito oversees death and the dead ('dead' in the souls universe seems to include things that are 'unalive.' Grave Warden Agdayne from the sequel implies that Death is the only real peace to be had in the Souls universe. Places like the Undead Crypt are kept lightless because light is what 'agitates' the dead. 

Contrary to what would seem obvious, Nito and the Dead don't like undeath any more than the living. Death should be peaceful, equitable, eternal, quiet, dark. You think they want a bunch of moaning zombies banging torches and axes around all day?

In the creation myth, a war against the elemental dragons during the Time of Ancients, Nito unleashed a “miasma of death and disease.' Death we just covered, but the disease part would seem to be poison. There are two types of 'poison' in the game, and one seems to relate to death as a sort of meta-physical concept, like “yeah, poison moss grows like crazy in the forest where fallen Oolacile once stood” while the other, toxin, seems to relate to situations like “yeah, our poop is crazy poisonous because we live in a fucking sewer full of bugs run by a cult that worship spiders where if you're lucky you get to eat rat.”

Speaking of rats, the lore behind Humanity is that it is/are fragmented bits of the Dark Soul and arose as the antipode of Gwyn's Lord's Soul, just as the Witch and Nito represent antipodal forces of life and death. The more Gwyn tries to keep the fire lit the deeper the shadows get, is the general idea. Humanity is often described as a nameless, mindless 'will,' a sort of gnawing ache akin to 'envy, or perhaps love,' and it's heavily implied that man's natural state is as a sort of empty golem vessel, a hollow, that tends to vacuum up stuff like stray souls and humanity. This 'will to light' (or fire or dark or whatever,) of humanity is usually directed towards things like, well, light, lightning, the sun, strength, glory, and Souls. As the husk picks up more and more humanity it grows more and more desperate for Souls. If a hollow has souls and no Humanity it becomes a 'cursed undead,' doomed to die and lose its Souls over and over as it slowly forgets everything it was. The only treatment for this is more Humanity. As the 'living' vessel collects more and more souls it also grows more of a personality and physical presence and sense of identity. Since this makes it a target for other Soul seekers, and also introduces abstract concepts like fear and treachery, it begins to chase Humanity in an effort to avoid losing its Souls and Hollowing. The more this back-and-forth is engaged in the more the character becomes open to the Abyss. The Abyss is a sort of critical mass between the forces of Dark and Light that causes things to mutate, Akira-like, into bizarre, chimeric abominations. 

Something very similar seems to happen between the forces of humanity and fire: Chaos.

Hollows, who have probably been around since the Age of Ancients, are perfectly happy to stand or lie in one spot staring at nothin' until the world ends so long as it isn't 'agitated,' at which point it reacts with what's colloquially known as Dredgling Beserker Attack: flailing wildly at the moving object with whatever happens to be in its hand in the stupid, it-works-but-it-shouldn't manner of a button masher in fighter games. Sometimes this results in the hollow collecting souls or, worse, humanity.

With souls you just have a hollow that hits hard, with humanity you have a hollow that hits hard and wants stuff.

...the Great Swamp is an abundant store of nature. You will understand, one day; it only takes time.
-Laurentius of the Great Swamp-

If you're familiar with Pratchett's 'Small Gods' then I liken hollows to the small gods, in that they're mindless, lifeless, directionless 'husks' drifting through a sort of gray non-existence, always hungry, always thirsting, not quite aware enough to do anything about the hunger or thirst; until, that is, they claim some humanity, which drives it to collect souls and eventually the "illusion of life,"  as Lord Aldia puts it, and runs around fucking things up for everybody until it's killed back into being a mindless hollow.

However.

Some humans are attracted to the hypnotic warmth of the Flame of Life, and eventually become pyromancers. These people are generally treated as untouchable and perverse outside of Lordran and the Great Swamp. This is despite, if Laurentius and Rosabeth are representative, being some of the nicest and most upbeat characters in the fiction. Even Eingyi turns out to be fairly pleasant once he realizes you share his devotion to the Fair Lady and the cause of chaos. Once the Flame is attached-which I would hazard is some sort of egg or larva-Souls that 'should' be used to strengthen the vessel are funnelled into the pyromancer's flame, which appears to be some kind of symbiotic parasite that converts souls, and eventually humanity, into fire.

Eingyi of the Great Swamp

It's worth noting that the poison, toxic, and acid cloud spells are all pyromancies and implied to only be usable after a person has contracted the egg-burdened status. The Toxic Mist pyromancy states that Eingyi was considered a heretic even by the standards of the Great Swamp and that he was driven from the swamp for developing such 'perverse diversions from the art of fire.' These mist or cloud spells seem to be created by some sort of breath attack. If I had to make a guess, based on the bloated pyromancers, I'd say that the 'mist' is waste from the chaos bug/larva being excreted, and these 'toxins' are actually the fuel for pyromancy. This would explain why chaos-related enemies are often, counter-intuitively, weak to fire damage. The Bloated Hollows of the Painted World, for example, won't explode in a toxic cloud upon death if killed with fire.

As with anything related to Dark Souls, when a young firebug begins down the path of pyromancy the second act of the 'play' is as unavoidable as it is horrifying.

It's implied, through item drops and locations, that enemies like the cragspiders and eggheads of the first game, and the darklurkers of the second game are the end results of dabbling with pyromancy.

If King Jeremiah's head is actually a wall-hugger-type chaos creature piloting a hollow around then that would go a long way towards explaining what happened in Izalith, at least after the attempt to split the First Flame. Both Jeremiah and 'Prince Izalit' are found near high-level pyromancies of a decidedly darker bent. Acid Surge, a cloud spell, is found near Jeremiah, and attributed to an 'outlander,' not Eingyi as the other cloud spells are, but not one from the Great Swamp. Power Within, found near the wall hugger, is attributed to Carmina, an apprentice to Salaman, who first learned pyromancy from Quelana. In order for Quelana to appear the player must have a pyromancy flame upgraded to +10. When the PC meets Quelana she expresses surprise that you, a 'walker of flesh,' are able to see her. This reminds her of a former pupil called Salaman the Great Fireball. Possibly the implication is that Jeremiah, his followers, and Carmina all voluntarily infected themselves with a 'second phase' chaos bug in order to access higher-level pyromancy, and their current appearance is a result of that. Conversely, it's possible that the wall-hugger 'Prince Izalit' was a lost prince of Izalith that killed Carmina when Carmina accepted Quelana's (or Salaman's) request to kill the Bed of Chaos, and his current position of fat, happy, and and with an endless supply of sewage is his reward. This infection causes, of course, the 'egghead' status which siphons off 50% of claimed souls before eventually 'growing' into an egg cluster. It's also a prerequisite for unlocking Eingyi's 'evil' pyromancies.

Eingyi is still in control of his own

Egg-burdened player character.

personality, while the other carriers and infested appear to be mindless supplicants enthralled by something like the Undead Rapport. To me, this states that everything Eingyi has done has been completely voluntary, and also that the infection doesn't always result in the destruction of the host's consciousness. Thorn Knight Kirk would seem to be another example of a 'sane' member of the Chaos Servants.

The egghead status can be cured with Egg Vermifuge, a chestnut that grows in Darkroot Garden (Oolacile,) along with various curative mosses. Its description states that 'the egg bearers have chosen to serve the Flame of Chaos, and the eggs symbolize this selfless choice.' However, it then goes on to state that 'these chestnuts are forbidden, but allowed under special circumstances.' I believe the implication here is that many egg-burdened quickly come to regret their decision, but the powers that be decided there were to be no backsies on this commitment. Eingyi is also the only reliable source for them outside of Darkroot, although one can be found on a corpse in the Painted World.

While regular pyromancies deal solely with flame, and cloud pyromancies seem to be perversions of 'regular' pyromancy, there is another class that works off of both humanity/Darkness and flame: Chaos.  

A pyromancer must be in tune with nature herself.

-Laurentius of the Great Swamp. 

If I could ask the Dark Souls team a single question it wouldn't be “Does the fact that Jeremiah drops lots of souls but no humanity indicate that he doesn't have any, or that he doesn't want any?” because there are better questions to ask, but I would like to know the answer. If pyromancers pursue the flame of chaos to the exclusion of the soul of light then they may not be driven by/for humanity beyond it's ability to lessen the suffering caused by the blight puss (I would guess that this is the toxic 'fuel' of pyromancy). It could be further extrapolated that, since Chaos Servant pyromancers are lukewarm or indifferent regarding humanity and souls as anything beyond a means to an end, that the parasite in fact consumes both while using the caster's pyromania to hold him or her in thrall. The 'human' we see is literally just a mindless hollow being steered by a bug that's tricking it into thinking this is what it wants.

The descriptions of the pyromancy flames, as well as Laurentius' dialogue, imply that the flames are both alive and 'a part of' the pyromancer' that feed on souls until they can be 'ascended,' and are generally viewed as unsavory.

The Fair Lady's Firekeeper Soul states that 'just below a thin layer of skin,

Humanity, as found in the Abyss.

are swarms of humanity that writhe and squirm. To her, the countless eggs which appeared were cradles for each tiny humanity.' From this we can gather that whatever these eggs eventually become-chaos eaters, chaos bugs, mosquitoes, leeches, pyro flames-they start out as eggs made of humanity. The "countless eggs which appeared" are probably people burning or offering her humanity, as she seems more or less completely blind and insensate to the outside world. I would suspect that the difference between regular and chaos is the difference between a Souls egg and a Humanity Egg. Likely they create the blightpuss as either excreta or some kind of spore or environmental fertilizer to render future 'volunteers' more pliable. Or at least less capable of escape. Finally, it's stated that pyromancy requires a lot of life and nature, and the reasons for this are hinted to be 'unsavoury.' This would fit with the rest of the hypothesis if this soul-to-flammable-poop-clouds conversion process is what's happening, as pyromancy requires a lot of souls/life and seem to create a lot of poison/toxins. 

Jeremiah's tattered yellow armor describes him as a 'legendary exile' and that 'no one knows where it came from.' In true Souls fashion, 'it' could refer to either the armor or Jeremiah himself. The most obvious explanation, given the chaos pyromancies, is that he was exiled from Izalith to the Painted World. However, there's no way of knowing if he was drawn into the painting during the original...commission or whatever, or if he made his way there later. This is further confounded by the fact that we don't even know when Izalith fell in relation to the creation of the painting, as both happened at a time beyond all memory. 

We can assume that Jeremiah and Priscilla know about each other. The position of Jeremiah's corpse seems to imply that their relationship wasn't antagonistic, but the layout of the level seems to indicate otherwise. Velka's Statue is a trigger that opens the path to Priscilla, and is being protected by the Phalanx above-ground and bonewheels below ground, with mostly pyromancers on the bonfire side and mostly crow people on the boss side. Additionally, a Berenike Knight and undead dragon are blocking the approach to Priscilla's chamber.

Here's what I think happened. Probably wrong. 

Jeremiah may have been the King of Izalith. Being a matriarchy (females are often the 'dominant' sex in the insect kingdom,) his position was probably little more than 'Head Egg-head,' and he probably only had any real power over slaves and laborers. I suspect that before the advent of Chaos males could never gain access to higher level pyromancies. As humanity would seem to favor males, perhaps this is why his...head? went out of control. Or maybe that's just normal for whatever he is. Either way, I think it's safe to say he's been around since at least before the rise of Quelana's pyromancy, possibly as early as the time of fire sorcery. I'd say the changeover between the two was caused by some kind of mass die off and evolutionary plateauing as the new Flame/Life soul caused a sort of Spellplague, with males emerging more powerful but still, theoretically, less powerful than females (remember, I'm talking about 7-limbed bugs that live in zombie heads here,) except the females seem to be going extinct.

He, Jeremiah, weaves pyromancies that predate the age of man and carries the tools of a torturer. I can't think of any more clear indication that he was present for the advent of the Old Chaos. Maybe he wasn't though. Maybe when pyromancers become too obviously bloated they get rounded up and shoved into the painting and that's why they're all here. I'm almost certain he's responsible for the impalings though, with Velka being the only other character I could even think of that may have done it, which wouldn't make a lot of sense. He spawns in the gateway between a graveyard and a killing field. Also, after watching a couple of fights against him, he seems to use the acid cloud pyromancy whenever the player hides behind the  metal shipping containers. He also has pretty terrible pathfinding, which you would expect if his eyes are 11' off the ground and slightly in front of his body.

The stakes in the garden, as well as the general mood and architecture, remind me a lot of the Night Attack of Târgovişte, where Vladislav III of Wallachia, outnumbered and without allies, waged a campaign of terror against Sultan Mehmet of the Turkish Ottomans. As the hordes drove ever further into the voivod's lands he was forced to implement ever more shocking scorched-earth tactics. Wells were poisoned, fields burnt, multitudes tortured. When one of Tepes' subjects fell ill they would be sent to Turkish settlements to propagate plague and tuberculosis. Among the Turk Vladislav came to be known as 'Kazıklı Bey.' 

His tactics were brilliant. But his number were few and his allies non-existent. The Turk advanced. An unending tide of men and gold and resources. Hungary turned him away. Moldavia, the promised sword to Wallachia's shield, would not honor their treaties. His family forsook him.  His younger brother, Radu the Beautiful, converted to Islam and defected to Turkey.

Fire, famine, and disease wracked the land. As the unending waves broke from Turkey Vladislav's genius for cruelty and psychological warfare reached a height of brutality and sadism seldom rivaled in human history.

The Sultan's armies massed within striking distance of the capital stronghold Târgovişte. The river had been taken. It was a siege.

Driven by fury at the cowardice and treachery he saw from his uneasy alliance with the Moldovan Domni, with the Sultan, by his brother Radu's betrayal, by the Ottoman who threatened his lands, his people, and his God. Alone, outnumbered, Wladislaus Dragwlya Vaivoda partium Transalpinarum knew his fortress could not withstand a siege, and did what was necessary. Raising muster he called "not only men of military age, but also of women and of children from the age of twelve up; and included Gypsy slave contingents."   

ad draconistarum iuuandum. 

In disguise and under cover of night, the lord of Wallachia sneaked into the enemy camp, spying out the Sultan's tent, their supply lines, garrisons,  and patrols.

Returning to his besieged city, Vlad gathered his meager army, farmers and shepherds, mercenaries and slaves, the few boyars who remained loyal to Wallachia. "It would be better that those who think of death should not follow me," the Dragon told his troops, and they were afraid.

But not of the Turk.

Legate Modrussa, recounting a tale told of the battle by a Wallachian veteran:

At nightfall Vlad penetrated into the Turkish camp with part of his troops...[where] the entire night he sped like lightning in every direction and caused great slaughter, so much so that, had the other commander to whom he had entrusted his remaining forces been equally brave, or had the Turks not fully obeyed the repeated orders from the sultan not to abandon their garrisons, the Wallachian undoubtedly would have gained the greatest and most brilliant victory. But the other commander (a boyar named Galeş) did not dare attack the camp from the other side as had been agreed upon...Vlad carried out an incredible massacre without losing many men in such a major encounter, though many were wounded. He abandoned the enemy camp before daybreak and returned to the same mountain from which he had come. No one dared pursue him, since he had caused such terror and turmoil. I learned by questioning those who had participated in this battle that the sultan lost all confidence in the situation. During that night the sultan abandoned the camp and fled in a shameful manner. And he would have continued to this way, had he not been reprimanded by his friends and brought back, almost against his will.

Recovering from the massacre, in which 3 to 4 Turkish soldiers fell for every Wallachian peasant lost, the Sultan broke camp and attacked the capital.

Sunset Tower, Târgovişte

The gates of Târgovişte lay open, the city abandoned. There, the Sultan found the Forest of the Dragon. 

Lining both sides of the capital road for a distance of—some say—60 miles, the Sultan saw the dead and dying bodies of some 20,000 impaled Turks hanging from stakes. For the better part of an hour the Turks marched the high road of Târgovişte, until they found, dangling from the highest stake, Bey (Lord,) Hamza Pasha, the Sultan's Vizier.

Mehmet quit the field, again, ordering men to dig a trench behind them to cover their escape. Command of operations in Wallachia were handed over to the traitor Radu the Beautiful, the Dragon's younger brother. 

Obviously, the scene of a cold, abandoned castle in the dark European mountains, with a forest of bodies on pikes, is a fairly 1:1 correlation with the Painted World-the architecture of the painting even skews towards the more haphazard style of eastern castles, in contrast to the more decorative and thoughtful western castles of Anor Londo. The presence of a ruthless warlord that relies on sadism, cruelty, terrorism, and scorched earth tactics to achieve their means, but could also be said to be indisputably brave, courageous, just (whatever that means,) sacrificing, and ambitious as a leader and ruler. Also, both Jeremiah and Vlad employ tactics we, in the modern age, refer to as terrorism. 'Terrorism tactics' are what, until recently, we called guerrilla warfare (or rebel activity, if we weren't sure if they were Good Guys or not yet, if they're not they become Radicals, if they are they're democratic,) and involved ruthless and extensively planned strikes executed by small groups that use shock, viciousness, fear, 'propaganda of the deed,' brutality, and paranoia to erode the enemies resolve, morale, resources, communication, infrastructure, logistics, supply lines and national reputation. 

Vaivoda Wladislaus Dragwlya, or Count Dracula, as he's known in the movies, was definitely one of the earliest and best examples of 'the press' playing a person's villainy/heroism up for political purposes. Vlad was a relatively minor lord of a war-plagued border-state sandwiched between Moldovia, who didn't particularly like or trust him, Hungary, who eventually had him imprisoned the next time he came around beating the drum; and Ottoman Turkey, who got along with Wallachia-Moldovia, historically, about as well as heavily armed Christians and Muslims always have done, although the Turkish Ottomans were probably the 'good guys' in the sense that they were slightly less savage at the time, ironically thanks to Rome's own buried history of philosophy and science. Europe at the time, remember, was going through the 'the rulers are all inbred thieves and the corrupt church, robber barons, and local tyrants run everything' period of monarchy.

Vlad was a warlord in every sense of the word. Brilliant, merciless, and with an intuitive understanding of the psychology of terror he himself seemed immune to. He was, from what I can tell, one of the first people in history to use black powder explosives as a military tactic. That kinda syncs up with Jeremiah, but I'm sure it's a coincidence. Beyond the man's cruelty, anger, and perfectionism the most remarked-upon thing about him was his intelligence. He seemed aware that he was an unreasonably cruel and abnormally sadistic person, but also seemed comfortable with it because of a sort of reflective evil genius for funneling his impulses into, depending on perspective, 'good' results. His people, while terrified of him, didn't seem to dislike him. He would brag that golden cups were left in the public fountains unguarded in his lands, for no Wallachian would dare turn his hand to thievery. His impalings were no mere haphazard 'spear-hoist' jobs, either. The stake was carefully lined up to wedge between the spine and the organs in order to minimize injury while maximizing suffering. Men (and women and children and the elderly,) on the stake were said to have died from starvation rather than blood loss, shock, or infection. Vlad would, during this time of suffering, eat his meals in front of these people while politely interrogating them, offering them food, drink, or a merciful death if they talked. 

Here was a man who spent his entire life in a situation where he should have been murdered every time he opened a door, and he managed to stand between two titanic and out of control religious empires with an army of terrified slaves and peasants, surrounded by countries that hated him, half of whom were ruled by his own family, and managed to be so singularly and horrifically good at it ('it' being his job, which most of the other voivodes and lords weren't bothering to do,) that he seized power against impossible odds three times before reportedly dying in battle. Not only that, but he was also condemned and praised by both the Ottoman and Roman leadership, often for the same things. Of the Night Battle a Venetian representative stated that "the whole of Christianity should celebrate Vlad Ţepeş's successful campaign." Of the same battle, Sultan Multi-Quit Mehmet II was reported to have been “seized with amazement and said that it was not possible to deprive of his country a man who had done such great deeds, who had such a diabolical understanding of how to govern his realm and its people. And he said that a man who had done such things was worth much." 

How does that connect to Jeremiah? Probably it doesn't. Probably some

General Sam's XKJ lore video

game designer just asked “hey, those 'bodies on pikes' assets with the creepy moaning? Can we put them here by the legally-not-the-Old Monk?" and that was that.

Still, it's hard not to see an overlap. 

A king of torture thought to be host to some demonic parasite. A 'beautiful' prince kept fat and indolent in the land of his enemies. Another prince, helpless, idiot, forgotten, alone in a pool of its own filth in a hole at the bottom of the world (I'm back in the game now, sorry,) with only the corpse of its sister for company. A hidden world of sin where even the statues weep, caught between titanic powers, in an isolated castle where was secreted a girl that even the Gods feared. A goddess of crows, her back turned to her daughter. Pale, tiny beings, cowering in corners, their flesh and humanity in tatters. A field of scorched earth in a forest of unending moans beneath foul trees. A sea of bodies, mouths open forever beneath the gray sky and black feathers of harried, ragged birds. A hidden, unknowable consciousness, beyond humanity and curses, and his merciless peasant warriors. A raging, seemingly endless font of soul-and-humanity-destroying wickedness: Lord of the flayed and the exiled and the betrayed and the wretched. 

His body. At peace beneath the Lifehunter, goddess of outcasts and sinners and all the tiny beings that cower and seethe in the forgotten burrows beneath our world. Free of thirst. Free of anger. Free of the cruelty he never chose but could never escape. 

Free of the Flame and all it demands.

Free of Humanity and all it corrupts. 

You do not belong here. 

So what the fuck is he doing there, specifically?

I don't know. I want to say that he's her Kirk, in that he seems to be Priscilla's champion, protecting her the way Garl Vinland protected Saint Astrea in Demon's Souls: with an ever-dwindling supply of resources, each 'chosen' undead weakening the ever-besieged Painted World.

Personally, and this is just me, I like to think that at one point in some distant, grey past, Jeremiah would have liked to have been known as Jeremiah the Wise. Or the Brave. Or the Peaceful. I think the Chaos awoke the Dark Soul in him, some primal impulse to seek a path where...what? Use of the Undead Rapport against hollows was banned? Chaos fire outlawed?

I doubt anyone in the Souls universe could aspire to something so pure.

Regardless, some path, whether accident of birth outrageous fortune or poor decision-making, led King Jeremiah to Sin. A crime against the Gods of One's Covenants.

Is that what opens us to the Abyss? Is that the crack in the world where the Old Chaos hides? Is that the heart of the unspeakable secret buried beneath Firelink?

There was a First Sin. I don't know what it was. I suspect. 

Gwyn feared the Dark, Humanity, and all it represents: Gwyn's own shadow. No light should shine eternal. 

The bonfire system reflects a covenant between the Four Lords of Lordran and the Four Kings of Man.

The names of the Kings are lost to the Abyss.

The bones of the Dead, the Sword of the Mighty, the Flames of the Mother, the Soul of one forgotten.

Call it Manus.

A spell to split the Flame. The same fire that burned the Archtrees cast by the tools that slew Dragons. A sacrifice. Necessary.

A Flame to burn forever, its roots running through the Four Kingdoms.

Oolacile the Mighty found It first. Buried beneath. In the Dark. 

Primeval Man, they called it. The Furtive Pygmy.

The font of Humanity and Want and Curse and Filth.

The grave of a God.

The first Sin?

Maybe. I also want to think that it was Seathe betraying his own. Anyway.

The ritual was set up. The First Flame would be split. 

Into Three.

The Accomplice would be named Steward to the affairs of the Fourth, granted a small duchy, and left to his research. Dissenters were to be exiled, a church established to spread the Gospel of the New Order.

Bonfires were set up across Lordran, probably using the roots of Archtrees to act as pumps. These were connected to the Kiln, which would burn the Sacrifice in the First Flame. This would convert the Sacrifice's soul into, of course, light and light and warmth and all that is good. The Dark will be conquered, the Flame renewed. A world of warmth and resplendence.

Firekeepers were set up at intervals to act as catch basins. One, directly above the Kiln, had to have her tongue removed, her ankles hobbled, and be built into an anchorhold.

What happens when a God kills his own shadow? What happens to its corpse?

The neat thing about Dark Souls is that maybe some of this stuff is right and maybe it isn't. It doesn't matter. Isn't that wonderful? It's not like science or "real" religion or math.

It worked, though. Kinda. The Flame stayed lit, things got nice for a while. Then Izalith fell. Then Oolacile. Then New Londo.

Or whichever. What gods could, fled.

What to do, Gwyn, what to do? Can't put Nito in the fire, he's been the one collecting the Dark Soul all these centuries. The Abyss would be everywhere. Instantly. 

You can't put the Witch in the bonfire system, the Witch is the bonfire system, or it's what's left of her host body, rather. Fire'd go out. 

Somewhere, a crow circles.

Welcome to Lordran.

Probably Jeremiah and Priscilla were casualties of all this, their course doomed centuries before they became aware of what happened, if they ever did. The bonfire system worked, but because it burned humanity on the bones of the dead it, oops, attracted hollows, chaos, and the Abyss: each abominations to their respective gods. because you can't have one without the other. 

Whatever happened in the Painted World I think it was what drove Jeremiah over the edge, not what came before. I think he had found one of the few safe places left. Found a Queen, and she a King. 

But it was in a dark and forgotten castle in a war-plagued border country. The gates were sealed, Jeremiah and his soldiers outside of it, Priscilla's crow people within. 

Centuries passed.

The gate stands still. Our goddess safe.

But at what price?

I think in the end he eventually fell to the Old Chaos. Probably Priscilla's Lifehunt ability was the only thing that kept it at bay. In the end, I imagine she saved him in the only way he could be saved.

Or he invaded and the crow people won the day, but barely. Or he's just some asshole that wandered in and couldn't wander back out. 

If Velka was responsible for the placement of the doll then that wouldn't make sense. She wouldn't want someone getting into the painting that could potentially hurt her daughter/followers. Or swipe her spells if Priscilla, of the slightly wing-y arms and rat-y tail and dragon-y skin, isn't her daughter.

Unless that's the only way Velka could get in herself. There seems to be some kind of conflict between Gwyndolin, in a tomb directly beneath the Painting, and Velka, whose Pardoner appears in the Undead Parish only after the first Bell of Awakening is rung. 

There's also the possibility that Jeremiah, Wall Hugger, and Ceaseless are three of an unknown number of fallen Izalith nobles, the same as Quelana, Quelaag, and the Fair Lady.

It's a puzzler, for sure.

I do know this though.

She's part rat. 

Probably part bird, too.