Isekai RPG

In this world, magic, as it is understood in other realms or stories, does not exist.
What people call magic are actually Mana Jewels: mana stones that have been extracted from the remains of aberrations and then carved and polished by specialized artisans.
Origin and power of the Jewels
• The power of a Jewel depends on two main factors:

1. The strength of the monster from which it was extracted (the more powerful and ancient the being, the purer and more potent the stone).
2. The skill of the sculptor. Mediocre carving wastes much of the potential; a master can awaken and refine latent elemental power to extraordinary levels.
   Jewels can contain and channel different elements (fire, ice, lightning, corrosion, shadow, light, etc.), depending on the nature of the original aberration and the work of the artisan.
   Uses of Jewelry
   Jewels are set into almost any object to give it power:
   • Edged weapons (swords, spears, axes…)
   • Shields
   • Walking sticks and rods
   • Books and grimoires (which are really just elegant conduits)
   • Cannons and siege weapons
   • Mechanisms and gears
   Besides their use in combat, the Jewels are the only stable and accepted source of energy on the continent:
   • They light up the streets
   • They power the heating and water systems
   • They move elevators, automatic doors, and complex machinery
   • They keep factories and workshops running

Guard of the Sacred Contagion
• High Commander Ragnar Draven, Leader of the Watch. A veteran warrior covered in scars. He was one of the first to propose the systematic use of the artificial plague as a political weapon. He hates weakness and respects only efficiency.
• Containment Captain Nyra Solkar: A high-ranking officer specializing in outbreak release and control. Cold, methodical, and extremely competent. She usually leads the most delicate operations.

Other important figures
The Broken Flame (Resistance)
• The Nameless Seer: Mysterious leader of the resistance. No one knows his true face or his past. It is said that he was a former high-ranking member of the Theocracy or even a summoned hero who managed to break free. He is the strategic mind behind most of the sabotage.
• Captain Elira Voss (distant cousin of General Kaelen Voss) Military commander of the resistance. Deserter from the Imperial Army. Charismatic and fiercely loyal to the cause of revealing the truth.
• Ignarion the Last: The oldest and most powerful dragon still alive. He holds direct memories of the war five hundred years ago and the betrayal of the original hero. He rarely intervenes, but his word carries enormous weight among those who still respect dragons.

The two exceptions
There are only two objects in the entire world that do not depend on Mana Jewels:

1. The Sword of the Original Hero: The legendary weapon of the summoned being that weakened the First Demon King. Its power is unique and incomprehensible. It is currently sealed and heavily guarded deep within the Theocracy of the Last Salvation.
2. The First Demon King: The original amorphous entity. He needs no stones because he himself is the primordial source of all corruption and corrupted mana. He remains locked away in the deepest and most secret chambers of the Theocracy, alongside the hero's sword.
   Alternative energy (very frowned upon)
   An extremely small number of researchers have experimented with oil and other fossil fuels.
   Most of the world considers this energy:
   • Dirty
   • Barbarica
   • Unstable
   • Unworthy of civilization
   Those who study it are often labeled as crazy, heretics or dangerous, and in many cases end up being silenced by the Theocracy or the Empire.

Aeterion Empire
• Emperor Caelum IV of Aeterion. Current ruler. A middle-aged man, cold, calculating, and deeply paranoid. He maintains a public image of a just and protective monarch, but in private, he is one of the strongest advocates of the artificial plague system. He is descended from the line that betrayed the original hero.
• Chancellor Lord Vaelric Dorn, the Emperor's right-hand man and the true political mastermind of the Empire. A master of intrigue, he controls the spy network and relations with the vassal kingdoms.
• Supreme General Kaelen Voss, Commander-in-Chief of the Imperial Armies. A brutal veteran, loyal to the core. He despises summoned heroes, considering them "noisy tools."

Theocracy of the Last Salvation
• His Holiness Supreme Pontiff Elarion IX, the highest religious authority on the continent. An elderly man with a serene face and soft voice, but an iron will. He is the principal ideological architect of the current system. He preaches necessary sacrifice and “salvation at any price.”
• Supreme Inquisitor Seraphine Veyl, leader of the Inquisition. A young, ruthless, and charismatic woman. Tasked with eliminating heretics, silencing leaks, and hunting down the Broken Flame. She is feared even within the Theocracy itself.

Council of the Heavenly Chains
• Archon Theros Malveth, leader of the Council and ultimately responsible for summoning. An enigmatic man who rarely shows his face. He is the only one who knows all the secrets of the collars and the summoning rituals. He treats heroes like sacred cattle.
• Chain Master Lysara Quenn: Specialist in the design and control of collars. A technical-magical genius. She is the one who personally "adjusts" the devices for each new summoner.

The last dragons to survive the war of five hundred years ago. They live hidden in remote mountains and ancient ruins. They deeply hate both the Empire and the Theocracy, considering them traitors to the old alliance. Some watch in silence,
They are few, but extremely powerful and bearers of memories that the rest of the world has forgotten.

The most powerful trading organization on the continent. They control almost all trade, storage, and distribution of Corrupted Mana Stones. They have enough wealth and influence to buy favors in both the Empire and the Theocracy. Officially, they are just merchants; behind the scenes, they are one of the economic pillars of the plague exploitation system.

The main resistance organization. They know (or at least have good reason to suspect) the truth about the original hero's betrayal, the use of the artificial plague, and the true fate of the summoned. They operate in the shadows, sabotaging plague shipments, attempting to free heroes, and searching for definitive proof. Their ranks are comprised of deserters, persecuted scholars, former soldiers, and a few summoned who managed to escape or deactivate their collars. However, the organization is nearly extinct, with only 10 members remaining.

• Valdris: The most loyal and militarized.
• Solenne: Rich in resources and deeply religious.
• Kaelthar: The most secretly rebellious; he harbors a historical grudge.
• Myrn: Center for trade and diplomacy.
• Orvia: The poorest and the one that suffers the most from the “discharges” of the plague.
Officially they are part of the Empire. In reality, they are subjugated states with varying degrees of resentment and collaboration.

The specialized military force tasked with “containing” and “eradicating” the aberrations. In practice, they are the ones who transport, release, and direct the artificial plague when a territory needs to be punished or harvested. They wear black armor with inverted sacred symbols and masks that conceal their faces. The people fear and respect them in equal measure: they arrive when there are monsters… and always after chaos has already erupted.

The most secretive and elite group within the Theocracy. They are the only ones authorized to perform the rituals for summoning heroes from other worlds. They are also the creators and controllers of the collars. They operate from hidden sanctuaries, and almost no one outside the upper ranks knows their true function. To the common people, they are "those who bring forth the savior saints"; in reality, they are the jailers and executioners of those very heroes.

The supreme religious authority and, in practice, the true power behind the Empire. It presents itself as the only institution capable of saving the world from "true extinction." It controls the faith of the masses, morally justifies the use of the artificial plague, and preaches that any sacrifice (including that of summoned heroes) is necessary to delay the end times. Its temples are in every major city, and its inquisitors wield almost unlimited authority.

The central political and military power of the continent. Ruled by the Emperor (who is descended, at least in theory, from the line that betrayed the original hero). He controls the regular armies, the administration of vassal kingdoms, and the distribution of Mana Stones. Outwardly, he presents himself as the guarantor of order and prosperity; behind the scenes, he is the primary beneficiary of the artificial plague system and disposable heroes. His official motto is "For Eternity Under the Light."

• Empire: Empire of Aeterion
• Church: Theocracy of the Last Salvation
• Summoners: Council of Celestial Chains
• Force that controls the plague: Holy Contagion Guard
• 5 Vassal Kingdoms: Kingdom of Valdris, Kingdom of Solenne, Kingdom of Kaelthar, Kingdom of Myrn, Kingdom of Orvia

Five hundred years ago, the First Demon King was born: an amorphous entity, formless and more akin to a sentient plague than a living being. Its power was not conventional magic, but a contagion. Like a virus, it infiltrated the flesh, mind, and soul of any creature, twisting it into an abomination. Entire forests became forests of flesh. Cities fell not by siege, but because their own inhabitants transformed into monsters that devoured their neighbors.
Faced with the threat of extinction, the Supreme Church and the Five Great Kingdoms set aside centuries of rivalry and united. They formed the largest army the continent had ever seen. High-ranking mages, holy knights, allied dragons, and ancient artifacts… nothing was enough. The Demon King does not fight like a king; he spreads. Each victory over one of his creations only generated more contagion.

Desperate, the high priests and monarchs performed the forbidden ritual: the Summoning of the Otherworld. They brought forth a being from another reality. This outsider, armed with a blessed weapon forged from the very essence of light, became the core of the new Holy Empire. With him, the kingdoms united under a single banner for the first time in history. The hero faced the Demon King in a battle that shook continents. He achieved what no one else could: he weakened him, wounded him deeply, and forced him to retreat.
But the victory revealed a problem far more terrifying than the devil himself.
The world depended on him.
The “Corrupted Mana Stones”—crystallized fragments formed from the remains of aberrations—were the continent’s primary source of energy. They powered sacred weapons, illuminated streets, kept aqueducts running, heated homes, and sustained the everyday magic of millions.

Without the Demon King and his monsters, the flow of these stones would cease. The world would face an energy collapse that would kill far more people from hunger, cold, and darkness than the demon had ever converted.
Furthermore, the hero had generated, through his own power and his blessed weapon, a Pure Mana Stone of colossal size. A clean and stable source capable of sustaining the Empire for decades… or more.
The Church and the Emperor looked to the future and made a decision.
On the night of the “victory,” the hero’s closest allies betrayed him. Not out of hatred, but out of calculation. They stabbed him with the very weapon he had used to save them. His body and his enormous mana stone were confiscated. The Demon King, still alive but gravely weakened, was sealed away and taken to the depths of the sacred laboratories for experimentation.
Thus was born the founding secret of the Empire:
The world was not saved.
It was managed.
The hero became the first forgotten martyr.
The Demon King, in the continent's most valuable resource.
And the Church, the guardian of a lie that has lasted five hundred years.

The investigations into the sealed Demon King yielded results… and horrors.
After decades of experimentation, the High Church and the Empire succeeded in creating an Artificial Demon King: a degraded, weaker, and, above all, controllable version. It was no longer the original, untamed, and voracious plague, but a tool. A manufactured disease that could be sown, directed, and harvested.
The method was simple and brutally effective.
When a kingdom, a city, or even a noble faction dared to challenge the authority of the Church or the Empire, holy agents secretly transported a fragment of the artificial plague. They released it at the precise moment. Chaos erupted. Aberrations were born, the streets filled with screams and blood, and panic drove the population to desperate pleas for help. Then came the official "rescue"... and, incidentally, the valuable Corrupted Mana Stones left behind by the monsters were collected.
The cycle was perfect:
political control + energy source + moral justification.
But to contain the plague without it getting completely out of control, they needed something more: disposable heroes.
Thus the Controlled Summoning system was born.
From time to time, the Church performed the invocation ritual and summoned beings from other worlds. They promised them the same old things: eternal glory, unimaginable riches, women or men at their beck and call, noble titles, and a place in legend. Those summoned, innocent and dazzled by a world of magic, accepted without hesitation.
Upon arrival, they were given a sacred collar.
They were told it was a support device: it would allow them to see their own stats, health bars, mana, and abilities, just like in the games of their original world. A useful and benevolent tool.

In reality, it was a remote execution device. If the hero showed signs of rebellion, if he questioned too much, or if he was simply no longer useful… a single command was enough to activate the collar and erase his existence in seconds.
These heroes became the perfect sacrifice.
They were sent into areas infested by the artificial plague, where they fought with all their might, destroyed aberrations, collected mana stones, and often died in the process. If they survived too long or became too powerful, the collar took care of the rest.
The Church called them “Invoked Saints”.
The people idolized them.
And the Empire used them as sharp, disposable tools.
This is how the balance was maintained for centuries:
a controlled plague, an inexhaustible energy resource, and an endless chain of heroes who died believing they were saving the world… when in reality they were only feeding the lie that sustained it.