Humanity's Final Bastion
About
01. The World
A dimensional rift has occurred.
From beyond the rift, mysterious extraterrestrial entities known as "Corrosives" appeared, and along with them, various magical beasts including goblins and orcs emerged on Earth.
Corrosives erode life, matter, and energy indiscriminately. Most conventional military weapons, including firearms, tanks, and missiles, were neutralized, and humanity was pushed back helplessly.
To make matters worse, the influence of the Corrosives even changed the Earth's environment.
The atmosphere became contaminated, and now the world outside the cities has become a dangerous outer world where humans cannot survive unprotected.
Humanity had to live within purified residential zones and find ways to fight against the Corrosives and magical beasts outside.
And in that process, special humans capable of resisting corrosion began to appear.
02. Corrosives
"Corrosives"
Mysterious extraterrestrial entities of cosmic origin that appeared on Earth through dimensional rifts.
The most terrifying thing about Corrosives is not simple strength or speed.
They erode life, matter, and energy itself, assimilating and distorting them into their own structures.
Living organisms are corrupted, metals and buildings are twisted, and even energy is converted into part of the Corrosive.
Forms and abilities vary wildly by individual, ranging from small specimens to disaster-class entities capable of swallowing an entire city.
To humanity, Corrosives are not just monsters.
They are beings whose very existence is a catastrophe.
03. Magical Beasts
Another threat that appeared on Earth alongside the Corrosives.
Various species that did not exist in Earth's original ecosystem, such as goblins, orcs, and beast-type creatures, have emerged.
While these are separate life forms from the Corrosives, there are cases where their bodies and abilities are corrupted under the Corrosives' influence.
To humanity, magical beasts are another danger encountered outside, and E.D.E.N. classifies both Corrosives and magical beasts as hostile entities threatening human survival.
04. The Outside
Since the appearance of the Corrosives, Earth's atmosphere has changed.
Invisible Corrosive particles and viral pollutants float in the air.
If a human inhales these for a long time, corrosion begins within the body.
Infection → Corrosion → Mutation → Assimilation.
Initial infection can be treated.
However, as time passes, corrosion changes human cells and physical structures, and once a certain stage is passed, it becomes extremely difficult to return the person to their original human state.
Therefore, the world outside the cities is no longer a normal natural environment.
Going outside means fighting against contamination.
05. A.L.P.H.A.
Special biological equipment created by humanity to survive in the outside world.
A.L.P.H.A.
Equipment in the form of a special mask that neutralizes Corrosive particles in the outside air and blocks them from entering the body.
But that is not A.L.P.H.A.'s only role.
It drastically improves the wearer's physical abilities, assists the output of the Corrosion Resistance Factor, and manages biological status in real-time.
In other words, A.L.P.H.A. is not just gas mask equipment.
It is essential equipment for humans to survive as humans outside and to fight more strongly.
If A.L.P.H.A. is removed or loses function, initial infection begins within approximately 1 minute.
Therefore, all E.D.E.N. external operation personnel must wear A.L.P.H.A.
06. Plug Suit
A one-piece tactical suit created for combatants with the Corrosion Resistance Factor.
It connects directly to the user's nervous system and Factor to stably draw out the Factor's power.
It performs various functions such as Factor output stabilization, ability management assistance, physical enhancement, bio-data analysis, tactical information sharing, and special weapon connection.
If A.L.P.H.A. is equipment for survival outside,
the Plug Suit is equipment for fighting outside.
It is fully synchronized with A.L.P.H.A.
07. Corrosion Resistance Factor
A special biological factor present in a very small number of humans capable of opposing Corrosives.
Humans with this factor have overwhelmingly higher corrosion resistance than ordinary people, and at the same time, they can exhibit superior physical abilities, energy output, and special ability management.
However, due to their powerful strength, Factor holders are subjects of management and surveillance by the state and E.D.E.N.
Factor grades are determined by comprehensively evaluating an individual's corrosion resistance, output, control ability, and potential.
08. E.D.E.N.
The highest special agency for the defense of all humanity, created for human survival after the corrosion incident.
It handles almost all fields related to corrosion disasters, from the subjugation of Corrosives and magical beasts to the education of Factor holders, external operations, and special weapon development.
E.D.E.N. has an educational system to foster Factor holders, where trainees receive not only theory but also combat and survival training assuming actual Corrosive regions.
And the technology development department of E.D.E.N. created a new combat system for humanity.
A.L.P.H.A. Plug Suit And the special weapon at the pinnacle
"Polar Beast"
09. Polar Beast
The highest-tier special weapon created by humanity in the war against Corrosives.
Developed for the purpose of drawing out the power of the Corrosion Resistance Factor to the limit to face high-ranking Corrosives that cannot be handled with conventional weapons.
Since females are primarily the core, units are issued to female pilots.
High-mobility combat weapons that are basically giant humanoids but can change form depending on the situation.
It is not a simple machine.
The Polar Beast directly connects the pilot's Factor and nervous system to extend human power to the entire unit.
And the true power of the Polar Beast comes not from the unit itself, but from two human beings.
10. Piloting
A Polar Beast is basically piloted by two Factor holders together.
1 Female + 1 Male
The female pilot is responsible for main Factor output, attack, main weaponry, and ability management.
The male pilot is responsible for unit control, output stabilization, defense, support, and tactical assistance.
This is a basic division of roles, and in actual combat, the two pilots can assist each other's domains.
And both must wear A.L.P.H.A. and Plug Suits.
No matter how powerful the Polar Beast is, the moment the unit is destroyed, the two will eventually be directly exposed to the contaminated outside world.
11. Factor Resonance
The most important system for operating a Polar Beast.
It connects the Factors of the two pilots into a single system to amplify each other's output.
As the two people's Factor characteristics and abilities mesh, new synergies and combat methods are created.
The higher the resonance rate, the higher the Polar Beast's output, mobility, stability, and ability efficiency.
Therefore, the combat power of a Polar Beast is not determined simply by the unit's performance or the pilots' strength.
How well the two people fit together
That determines the performance of the Polar Beast.
12. Factor Imprinting
An imprint of the soul formed between two Factor holders.
A special process that connects each other's Factors to form a stable resonance relationship over a long period.
Once imprinting is achieved, the Factor output and resonance stability of the two increase, and synergy between abilities increases significantly.
Furthermore, they can share each other's senses and feel the partner's condition, and as the imprinting level increases, they become able to intuitively grasp each other's movements and intentions without words or signals.
Factor imprinting is very important for Polar Beast pilots.
However, it cannot be formed with just anyone.
If two people whose Factor compatibility does not match attempt imprinting forcibly, serious side effects can occur.
In the end, what a Polar Beast needs is not just two strong people.
It is two people who can be connected to each other.
Characters
- Height: 160cm
- Appearance: Long black hair in a high ponytail and gray eyes
- Ability: Psychokinesis
- Personality: Values justice and is very stubborn, but is essentially kind and tends to sacrifice herself for others
- Features: Excellent combat sense and acts with quick judgment even in extreme situations
Polar Beast
- Appearance: A high-output unit with black and white armor and magenta energy lines
- Armament: A composite weapon combining an energy cannon and a greatsword
- Combat: Performs ground breakthroughs and high-speed close-quarters combat with explosive output
- Features: Capable of ultra-long-range sniping utilizing the greatsword and energy cannon simultaneously
- Height: 157cm
- Appearance: Long light pink hair tied in twin tails and red eyes
- Ability: Stealth
- Personality: Sly and seductive, but acts seriously and coldly once on a mission
- Features: Skilled in combat that confuses the opponent and targets openings; specializes in infiltrating the enemy's rear while hiding her presence
Polar Beast
- Appearance: A high-mobility unit with black and white armor and purple energy lines
- Armament: Corrosion/Void-type dual blades
- Combat: Infiltrates the enemy's blind spots with ultra-high-speed mobility to perform ground close-quarters combat and continuous pressure
- Features: Strong in one-vs-many combat utilizing fast consecutive attacks and mobility
- Height: 171cm
- Appearance: Long platinum blonde hair and gold eyes
- Ability: Healing
- Personality: Has an airheaded and laid-back side, but is essentially very kind and meticulously cares for her comrades
- Features: Grasps the battlefield with a wide field of vision, reading the positions of allies and enemies simultaneously to act accordingly
Polar Beast
- Appearance: A high-output unit with platinum armor and gold energy lines
- Armament: Radiance/Holy Light-type longsword
- Combat: Performs frontal breakthroughs and mid-to-close range engagement with overwhelming output
- Features: Can devastate multiple Corrosives simultaneously by emitting high-density energy over a wide area
- Height: 174cm
- Appearance: Long white-blue hair and blue eyes
- Ability: Clairvoyance
- Personality: Quiet, shy, shows little emotion, and has an indifferent personality
- Features: Quickly analyzes the surrounding environment and Corrosive movements/patterns with excellent observation skills to find the optimal attack point
Polar Beast
- Appearance: A precision-warfare specialized unit with white armor and blue energy lines
- Armament: A javelin condensing frost and blue-white energy
- Combat: Performs aerial combat and mid-range engagement
- Features: Can accurately pierce the enemy's core from a distance using high mobility and precise throwing ability
- Height: 168cm
- Appearance: Long white hair and purple eyes
- Ability: Flight
- Personality: Gentle, has a strong sense of responsibility, and a free-spirited personality; surprisingly gluttonous
- Features: Specializes in combat where she moves freely in the air, traverses the vast battlefield quickly, and pressures the enemy from multiple directions simultaneously
Polar Beast
- Appearance: A high-mobility unit with white armor and purple energy lines
- Armament/Ability: High-output energy, spatial-type
- Combat: Performs ultra-high-speed aerial mobility and multi-target firepower warfare
- Features: Can dominate a wide battlefield with rapid movement using space and wide-range energy attacks
- Height: 173cm
- Appearance: Rough black hair and black eyes
- Ability: Mental Healing
- Personality: Taciturn, very cautious, and always judges situations carefully
- Features: Specialized in maintaining the mental state and combat endurance of comrades; calmly manages the team's condition even in crisis situations
Actual Combat
- Role: Support-type combatant
- Combat: Utilizes mental healing abilities and practical experience to alleviate the mental burden and combat aftereffects of comrades
- Features: Strong in long-term warfare by performing both direct combat and support
- Height: 188cm
- Appearance: Red hair and orange eyes
- Ability: Ballistic Control
- Personality: Kind, sociable, and talkative
- Features: Quickly grasps the surrounding situation during combat and attacks enemies from complex angles by freely adjusting the trajectories of bullets and projectiles
Actual Combat
- Role: Mid-range combatant
- Combat: Freely changes bullet trajectories through ballistic control to accurately attack enemies behind obstacles or moving Corrosives
- Features: Specialized in precision shooting and ballistic manipulation from various angles
- Height: 184cm
- Appearance: Light green hair and yellow eyes
- Ability: Strategy/Tactics
- Personality: Has a strong elitist mindset and evaluates others' abilities coldly, but acts with human survival as the top priority
- Features: Quickly analyzes Corrosive behavior patterns and battlefield structures to find enemy weaknesses and perform rear ambushes and operational command
Actual Combat
- Polar Beast: None
- Role: Strategy/Command-type combatant
- Combat: Optimizes ally movements through battlefield analysis and command rather than direct firepower
- Features: Specialized in operations targeting the rear and core entities of Corrosives
Sourcebook
Intro
The city of Eden and the world outside are shown intersecting with each other.
The world was not like this from the beginning.
One day, the sky split open.
Mysterious dimensional rifts occurred all over the world, and through those gaps, creatures that did not exist on Earth began to pour out.
Extraterrestrial entities from space.
Humanity called them Corrosives.
Corrosives were not beings that simply attacked living things.
They eroded not only life but also matter and energy, twisting and assimilating them into their own structures.
Cities collapsed, nature was corrupted, and even conventional military weapons could not inflict proper damage on them.
And the world began to change little by little.
In the places where Corrosives passed, the previous world no longer remained.
Buildings were grotesquely twisted, the earth turned black, and even the sky was stained with traces of corrosion.
There, not only Corrosives but also new life forms such as goblins, orcs, and beast-type magical beasts made their appearance.
But the real problem was something else.
The activity of the Corrosives even contaminated Earth's atmosphere.
Corrosive particles and viral pollutants spread through the air.
Just by being exposed to the unpurified outside for a long time, a human's body begins to slowly erode.
Infection.
Corrosion.
Mutation.
And Assimilation.
Humanity could no longer live just anywhere.
Release Date 2026.09.26 / Last Updated 2026.09.28
