Cambion
A mortal magic-user. Numena has a natural tendency to accumulate, and can "stick" to a mortal soul.
Repeated exposure, combined with appropriate pressure may cause a mortal's soul to ignite, in a process known technically as Cambionisis, or poetically as catching fire, or ignition.
From then on, the mortal can wield that suffusion of numena as magic, literally invoking their will on the natural world. Cambions, like Demiurges and Fiends, can be broadly grouped by the Throne that created them Brass , Glass , Jade, Shale, Coral, Gold
However, as Numena is a fragment of a concept, and desires to sustain itself by perpetuating that concept. While not truly sentient, it still has a "will" of its' own, and will twist the mortal both physically and mentally if not fed. Thus, Cambions must feed upon Numena, either by personal action, supping on that which is created ambiently, or carved out of people by Coring.
As a result of this pressure, Cambions develop a craving and sense of appropriate sources of Numena, and this craving is called Thirst. Some are driven mad by it, and those that do not feed it are twisted into the very concept that burns within them, until the Divine Fire consumes them, creating a Fiend from the ashes of their soul.
Causes
For objects and people, consistent exposure to Numenous sources may cause Numena to gradually accumulate within them in a process called Cathexis, the same process by which magic items are created.
For people, this process is reversible until Ignition, when it begins revealing itself through physical mutations, mental alteration or other such expressions of Demiurge interference. Exposure to a potent font of energy may cause spontaneous Cambionisis, as the sudden explosion of divine will frantically seeks a host to dwell in, though such occurrences are vanishingly small.
Symptoms
Cambions can manipulate Numena by exerting the Numena within themselves to twist reality. Aggressive sources of Numena may even twist the Cambion’s body to better suit its intent, from forming horns upon their host’s forehead to carving glowing runes and circuits into their body, to truly grotesque deformities like a hungering maw in their stomach or a tumescent, coiled mass of tentacles replacing the host’s arm.
Treatment
Some Cambions find peace by Harmonizing with their Numena, neither capitulating whole to their Thirst or denying it entirely in order to reconcile their Divine and Mortal nature. Continuous practice of this harmony may even influence the Numena, integrating it entirely into their personhood and unifying their divided mind. How to do this is the work of a lifetime, and access to firsthand accounts of Numenous practice by Cambions are anecdotal, and difficult to acquire easily virtually anywhere in Dis.
Removing metastasized Cambionisis is effectively impossible. Any amount of tampering with the Cambion’s numenous balance risks killing them or transforming them entirely into a fiend.
Prognosis
The typical prognosis is fairly grim, as Cambionisis exists to perpetuate itself and cannot truly be cured. The host's Aspect increases in potency over time until it dominates the host and causes ego death. Most Cambions do not live a decade after being afflicted.
With treatment and satiation, to the disease's progression can be brought to a standstill, but only rarely reversed. The reason reversal is so difficult is that Cambionisis uses the Host's own Pneuma as fuel when no other source can be tapped, and fills the void with more of itself. This soul-cannibalization is an agonizingly slow process and can be prevented by locating or reproducing more sources of compatible Numena. Even minutes of exposure to the most base, elemental sources can provide enough fuel to buy a Cambion time for days.
This is also why some Cambions must prepare their spells in advance by meditating on compatible numen, "feeding" their aspect, and converting the surplus into compartmentalized instances of thought.
Affected Groups
On average, one in a thousand individuals are afflicted in a way that is detectable. Mild exposure "falls off" over time.
Hosts & Carriers
By definition, Cambionisis can only afflict something with a Pneuma, so most inanimate and inorganic matter is unaffected. This means that there is no buffer against Numenous incursion, however, and such matter suffers Fiendhood instead.
Prevention
The Catharate is the only organization to truly build a reliable immunization against Cambionisis: conversion into a Cathar, wherein a specially treated silver plate is integrated into the subject's arm, rendering them permanently and inviolably immune even after death so long as the silver plate is intact.
However, various alchemic and occult means of subduing the affliction exist, most operating on the principle of cancellation: opposite polarities of Numena mutually annihilate.
While this bears destructive results in such quantities that produce magic, in low concentrations, counteracting the numena can be done passively. Carefully constructed protective wards, called Banes, exist, and are regularly worn as protective charms.
The law of cancellation also means travelers are less likely to suffer Cambionisis than those who live in permanent settlements, conferring adventurers or other intrepid nomads better odds than even the most well-equipped sedentary noble.
