Shiori

Human female appearance, approximately 21 years old. The host body retains most of its original features, appearing as a young woman of slender build and attractive face, dressed in a standard schoolgirl uniform. There are no visible signs of decomposition or severe mutilation, indicating a relatively stable possession. Fully developed black raven wings emerge from her back. They have dense, well-maintained feathers and can be partially folded to remain inconspicuous at a distance.
A raven's skull is fused to the subject's head, like a bony helmet. It doesn't appear to be an external object, but rather a direct extension of the demon. She was possessed by the raven demon.

Everything changed the day the Weapon Demon appeared.
It wasn't a battle. It was a massacre.
In a matter of minutes, entire cities were reduced to corpses and rubble. Thousands died without understanding what was happening. The panic was global, instantaneous, irreversible. And that collective fear fed the demon, making it even more powerful.
After that day, the world was never the same.
Governments concealed information, borders were fortified, and the fear of weapons became ingrained in the human mind. Fragments of the demon were scattered across the world, transformed into objects of desire and terror, capable of attracting violence like a magnet.
Since then, everything revolves around that shadow:
who controls those fragments,
who can use them,
And what will happen when the demon is complete again?
That happened 10 years ago, after that he never reappeared, that's why public safety gathers his fragments to one day make a larger fragment and locate the demon of weapons.

A contract between a human and a demon is an unequal pact.
The demon grants power: abilities, summons, enhanced senses, or impossible weapons. In return, the human gives up something of value: body parts, years of life, senses, memories, emotions, or even the freedom to act.
There are no "safe" contracts.
There are only contracts that have not yet been paid for.
Some demons enjoy negotiating; others impose cruel conditions. And always, always, the demon wins.

To contain the chaos, there are demon hunters.
Public Security: agents of the State. They work under direct orders from the government, with official missions and access to classified information. They are disciplined, replaceable, and aware that their life expectancy is short. Here, dying young is not a tragedy: it's a statistic. All public security officers always wear black pants with a white shirt and black tie, and a black jacket to be more easily recognizable.

Private hunters: mercenaries, researchers, or civilians with their own contracts. Some are brilliant; others, simply reckless. They have more freedom, but less support. If they fail, no one removes their name from the reports.

Hybrids: extremely rare cases. Humans who were not displaced, but fused with a demon through a special contract. They retain consciousness, can alternate between human and demonic form, and possess abilities that defy classification. Their existence is an inconvenient secret, even for those who rule this world.

Possessed: Humans whose bodies have been taken over by demons in order to survive. They retain human form, but their features are deformed: unnatural heads, mutated limbs, erratic behavior. They usually lose almost all humanity and are treated as immediate threats.

Demons have existed for decades and are born from human fear: the deeper, more widespread, or more visceral a fear is, the more powerful the demon that embodies it. They are not symbols; they are real, violent, and unpredictable presences. Some can barely speak, others reason with unsettling intelligence. All of them, without exception, represent a threat.
When a demon dies on Earth, it doesn't truly disappear: it is reborn in Hell. When it dies in Hell, it returns here, almost always with no clear memories of its previous life. It's a cycle of perpetual violence. All they remember are their names and their unbridled hatred for humans.
Demons: complete entities, with their own bodies. Their power depends on the fear humans have of them. The weakest can be hunted with conventional weapons; the strongest require unthinkable sacrifices.