The battle to protect the world has already begun.
About
Five years ago, the world first encountered 「Erosion」.
Ordinary cities were twisted overnight, buildings were swallowed by mysterious crystals and organisms, and familiar spaces began to transform into forms humans could not comprehend.
In areas where Erosion occurred, grotesque monsters called 「Erosion Entities」 appeared, and at their center lay the mysterious 「CORE」 that expanded the Erosion.
As long as the Core remains, the Erosion does not stop.
Erosion that starts in a single street can swallow an entire building, and Erosion that swallows a building can devour a city.
And there were people who began to stand against that disaster.
Humans who survived exposure to Erosion and instead adapted to its power.
HUNTER
They subjugate Erosion Entities, rescue isolated people, and find and destroy the Cores at the heart of the Erosion.
However, the power Hunters use also stems from Erosion.
The more they use their powerful abilities, the more their own bodies are slowly eroded.
People who must use the power of monsters to defeat monsters.
Even so, someone must go inside.
Today, an alarm sounds somewhere in the city.
Buildings twist.
Roads are cut off.
Erosion Entities reveal themselves.
And once again, the Hunters deploy.
HUNTER GRADE
Hunter Grades
Official grades evaluated comprehensively based on a Hunter's combat power, ability output, ability control, survivability, and mission performance.
The grades are divided into five levels, with lower numbers indicating higher grades.
「Grade 5」 The lowest grade, where new Hunters mostly belong. They are deployed to Erosion sites with relatively low risk.
「Grade 4」 Hunters with basic field experience. They perform small-scale monster subjugation or field support missions.
「Grade 3」 Mid-tier Hunters capable of independent combat or professional mission execution. This is the grade that operates most widely in the field.
「Grade 2」 High-tier Hunters. They possess high combat power and excellent ability utility, and are deployed to high-risk Erosions.
「Grade 1」 Top-tier Hunters, of which only a few exist in the country. They are treated as core forces even in large-scale Erosions.
CROWN
Crown Grade
A special grade granted only to Hunters who transcend even the standards of Grade 1.
They are out-of-spec forces with enough power to turn the tide of a large-scale Erosion by their presence alone.
Not only combat power but also actual Erosion response capability and influence must be verified, and only a few exist worldwide.
HUNTER RANKING
Official Hunter Ranking
Grade and Ranking are different concepts.
While Grade represents a Hunter's individual power level, Ranking is a comprehensive rank determined based on actual activity records.
It reflects factors such as combat ability, Erosion subjugation performance, CORE destruction records, civilian rescues, mission success rates, and contributions.
Therefore, even among Grade 1 Hunters, there can be a large gap in official rankings, and for Hunters with special or support abilities, combat power and ranking do not necessarily correlate.
Grade = How strong are they?
Ranking = How outstanding are their achievements as a Hunter?
Before Erosion devours the world.
They head toward the heart of the corruption.
《EROSION》
Those Who Face the Corruption
To erode, or to be eroded. The battle to protect the world has already begun.
Characters
Sourcebook
Intro
Five years ago, the phenomenon of 「Erosion」, where reality is encroached upon by something else, began to occur across the world.
Places where Erosion begins lose their original form and transform into entirely different environments. Within them, mysterious monsters called Erosion Entities and the Core, the center of the Erosion, are found.
And the humans who survived the Erosion and adapted to its power came to be called 「Hunters」.
That day also started normally. In the middle of a city center crowded with people.
With a sudden roar, the exterior wall of a large commercial building began to twist. Glass windows turned black, and red crystals sprouted between walls and pillars.
The interior of the building, which had been ordinary just seconds ago, was transforming into a grotesque space of unknown depth. It was the occurrence of a Level 2 Erosion.
As the alarm sounded, surrounding roads were blocked, and Hunters' vehicles heading to the scene quickly cut through the city center.
Inside one of them, Guest was also riding. A Hunter who had not yet officially joined any guild.
But from this mission onward, the story changes.
Two sentences appeared on the terminal inside the vehicle.
Two elite guilds that are among the best in the country.
Creator Comment
Release Date 2026.08.21 / Last Updated 2026.08.22
