The Abyss

Source of all fiends, and the ultimate destination for the most wicked mortal souls.

A violent, malevolent place where the strong survive on the backs of the weak, the weak conspire to overthrow the strong, alliances only last while convenient, and the landscape itself tortures the mind and body of all who dare to pass.

Cosmology
Aside from Mechanus, the Abyss is the most difficult plane to access from the Nexus, on par with the Heavens. It's location in the Planarverse is perfectly opposite to the Heavens.

Time in the Abyss passes faster than on the PM Plane. The most famous case of this phenomena being observed is when St. Sanguinnius was rescued after spending months imprisoned in the Abyss, and had physically aged years during that time.

Fiendish Feudalism
When a soul is sent to the Abyss it is either consumed by a fiend, or becomes a pitifully weak fiend without any memories. If these lowly fiends are able to devour their kin without being preyed upon themselves they will eventually develop a more threatening form, and their form only becomes more imposing as they amass more power. Weaker fiends are usually in service to a stronger fiend, be it willingly or by force.

Wretched Reincarnation
When a fiend is slain on another plain it spawns back in the Abyss in the same pitiful form it was given when it died as a mortal, but this time it retains all the memories of its life as a fiend. These memories give the fiend an edge over those who do not yet understand the ways of the Abyss, making it easier to regain the level of power they once held. That said, this would take many years and most fiends in this position will be consumed by others while they are still weak.

Fiendish Races
There are two main fiendish races, Demons and Devils. These terms are often used interchangeably due to the difficulty involved in distinguishing the two. In broad terms, Devils are more methodical, and Demons are more brutish. The differences in personality can make it difficult for Demons and Devils to cooperate, however they can often both be found in the same Abyssal Domain. Fiends that are not Demons, Devils, or Yugoloths are the result of a fiend being conceived or created on a plane outside of the Abyss.

As the reincarnations of the most wicked souls in the cosmos, fiends are categorically evil. They also don’t appear to age, but given the nature of their plane they rarely live too long anyway.

Abyssal Domains
The structure of the Abyss is different from any other plane. It is made up of countless sub-planes known as domains which drift across the Abyss, occasionally colliding and sparking conflict

Domains are created when a fiend accrues significant power and influence within the Abyss. Doing so allows them to shape the Abyss in their own image, changing the plane as it sees fit.

Each domain is capable of drastically altering the fiends that come to occupy it. Their color, magical abilities, physiology, and behavior are all changed to more closely resemble the domain's fiendish lord. When an Abyssal Lord dies, their Domain is either carried on by the most powerful fiend remaining in it, or it ceases to exist. Due to the treacherous nature of fiends, domains and Abyssal Lords are constantly emerging and being killed.

Fiends that do not belong to a domain are not as strongly tethered to the Abyss, and typically easier to influence and manipulate. Because of this most fiends seen on the PM Plane are domainless and do not bear the signature mutations that domains impart.

Feuding Fiends
The only reason why the boundless armies of the Abyss don’t siege across the planes and conquer everything is because they are even worse at cooperating than mortals. The Abyssal Domains are constantly waging war against each other, and many domains also deal with prolific in-fighting on top of that. This manages to stabilize the fiendish population somewhat, as well as redirect their attention away from the woefully unprepared residents of the other planes.

Notable Domains
Certain Abyssal Domains have been plaguing the Prime Material plane for centuries. The ruling Abyssal Lords and the mutations they cause are both well documented.

Torment Domain
 Lord: Sarmenti 

The most notorious Abyssal Lord is by far Sarmenti the Demogorgon. He has an obsession with physically and mentally torturing sentient beings until they become unrecoverably insane, especially humans.

Sarmenti himself is so horrid that the mere sight of him can drive mortals into a fear-fueled delirium. He is a massive red quilled beast with two simian heads, and at least one of them is cackling at any given moment. His back is spined with the same kind of iron hooks that litter his domain. His arms take the form of multiple giant iron chains that end in more barbed hooks, which he is capable of moving like tendrils.

The incident that pushed his name into infamy was his abduction of the famous Dawn Knight St. Sanguinnius, and the harrowing rescue mission that followed.

 Fiends: Tormentors 

The crimson fiends in Sarmenti’s domain reflect his sadistic nature, being covered in hooks and barbed stingers and possessing magic that directly targets the mind.

Tormentors are just as twisted as their name implies, and rarely grant their victims a quick death. The few victims who survive a Tormentor raid are brought back to the Torment Domain to face a much worse fate. These poor lot become Sarmenti’s personal playthings, having their lives preserved by unnatural means so they can stay on the receiving end of Sarmenti’s sadism for thousands of years.

 Domain’s Appearance 

The Torment Domain is filled with living people hung on iron hooks and ongoing experiments to develop new forms of torture.

Plague Domain
 Lords: Virions 

Rather than being led by a single lord, the Plague Domain is led by a legion of identically powerful fiends. The Virions are gargantuan stationary lampre-like creatures that are constantly devouring souls and fiends and producing their diseased hordes. The seemingly thoughtless nature of the Virions has led some demonologists to believe that they lack sentience, and are simply driven to propagate themselves much like the diseases they spread.

 Fiends: Plaguebearers 

All fiends within the plague domain are repulsive, sickly green, and coated in rotting flesh and infectious pus. This domain is responsible for the most devastating plagues in the Nexus's history, and a single plaguebearer can start an epidemic that claims the lives of hundreds.

 Domain’s Appearance 

The domain itself is mostly empty, free of the towering and disorienting sort of structures present in most domains. The only structures present on its vast stretches of barren land are small huts where plaguecrafters are constantly at work developing the latest sicknesses.

Silence Domain
 Lords: Bludgoons 

The Silence Domain is headed by a demonic legion of identical hulking brutes. They are often too preoccupied trying to beat each other to death to provide any actual leadership, but the influence they project onto their domain is clear.

Due to the apparent absence of intelligence in Bludgoons and other silencer demons it is theorized that they are created from animal souls, or the result of humanoid souls being split into multiple demons.

 Fiends: Silencer Demons 

The Silence Domain is driven by pure destruction. Silencer demons possess terrifying physical might. They are also dead silent, they lack any mouths, and the noise from their rampages is magically suppressed. Because of this, a town can be demolished by silencer demons during the night without ever being aware they were under attack. The dark hues of their skin, armor, and fur further increases their unintentional aptitude for stealth.

 Domain’s Appearance 

The Silence Domain is a sprawling series of dimly lit fighting arenas where the mute demons will spend their time fighting either each other or their captives.

Gehenna Domain
 Lord: Unknown 

Gehenna is the only Abyssal domain of such renown that still has not had their lord or lords identified. It is presumed that he is a very selfish and powerful fiend, whose form is somehow perfectly adapted for the role of an Abyssal Lord. Some also theorize that there is no Lord, and that the collective thirst for wealth amongst the Yugoloths is strong enough to create a domain without the need for a lord. This goes against the current understanding of domains, but so does a lot of things about Yugoloths.

 Fiends: Yugoloths 

While previously obscure since the War of Unification Gehenna has become the most widely known abyssal domain by far. Gehenna is in many ways an oddity amongst the other Abyssal domains. Other domains are made up of devils and/or demons, but Yugoloths lie somewhere in between. Furthermore while other fiends are obsessed with intangible or alien objectives like power or obtaining souls, Yugoloths are obsessed with worldly desires, most prominently wealth. Adding to their peculiarity even more, Yugoloths vary widely in both appearance and behavior despite being members of the same domain.

Yugoloths serve as fiendish sell swords. While their prices are exorbitant, one would be hard pressed to find a more competent hired hand. Their varied appearances and personalities stem from their highly specialized forms.

 Domain’s Appearance 

Gehenna offers the most familiar landscape to PM denizens. It consists of multiple separate guild halls where the fiends reside based on their specialization.

Contract Domain
 Lord: Cozenmulct 

The Abyssal Lord of the Contract Domain is Cozenmulct the Slime. Unlike the alluring or intimidating appearances of his minions, Cozenmulct looks as disgusting as he is pitiful. He resembles a massive slug with arms and humanoid eyes, and a humanoid skeleton is visible through his semitransparent body. He also constantly oozes a putrid slime, which appears to be a mixture of feces and blood.

It is believed that the skeleton within Cozenmulct is what remains of his original, more beautiful form. After he broke a contract he made with a mortal favored by the Prime, the god of law put a curse on Cozenmulct to make him appearance reflect his wicked intentions and prevent him from ever again using his looks and charms to manipulate someone. From this point on any devil that broke their contract was transformed into a hideous blob of cells, these became the first oozes.

 Fiends: Contractor Devils 

Fiends are notorious for offering tempting contracts to desperate mortals. Before the War of Unification made Yugoloths a common sight, the devils of the Contract Domain were the most notorious culprits of this. Whereas Yugoloths generally ask for exorbitant monetary fees, contractors typically ask for the signer’s soul. Additionally, instead of personally performing some kind of service for the signer as Yugoloths do, contractors grant them some kind of benefit such as wealth or strength.

Like Yugoloths, there are many different types of contractors that are tailored to serve different objectives.

The ways the Contract Domain alters fiends are more subtle than most other domains. Contract devils are made more intelligent, charismatic, and capable of speaking nearly any mortal language. Contractors are also more prone to wearing armor and clothing than other fiends.

The higher ups of the Contract Domain are constantly in flux, as the power hungry peons orchestrate cunning schemes to assassinate their superiors and seize authority. Cozenmulct actively encourages this behavior, and the fact he has remained the Lord for so long despite the treachery of his minions is a point of pride for him.

 Domain’s Appearance 

The Contract Domain is the concept of bureaucracy given material form. Maze-like corridors and offices lined with rules and guidelines posted on the walls.