Third planet of the solar system, the blue planet, Earth.
A message drifted through space. Abandoned by humanity in the hope that some civilization would find and translate it in the future.
[Throughout the existence of the human race, demons have existed. There are records from at least seven thousand years ago mentioning entities like daemons. The ancients used to say that all wars, conflicts, and strife in humanity were caused by this race lurking beneath the ground—twisting through the darkness and feeding on souls.
It could be said that for all these millennia, they fed on sloth. They made us irritable to fuel wrath. They filled us with arrogance for pride, invented ever more jewels to drown us in lust.
We always placed ourselves in God's hands. Yet nowadays, we question Him…
Twenty years after World War II, the demons took advantage of the cracks left in humanity to act as they had planned.
Marks consumed countries, like tracks being slowly laid. For years, it was like this. Each day, the marks on the world grew larger, stronger. Though they appeared physical, they were not. Nothing could touch them; they were made of pure energy, yet they did not belong to our world.
Nothing humanity tried worked. In total, there were seven marks. Seven sigils. One for each continent, with only one isolated in the sea. Our species could only wait. We let time tell us what would happen, while people lived their lives normally. We were still recovering from the Second World War, so for most, it was accidentally pushed into the background—since, at the time, it posed no apparent threat.
Decades after their appearance, the marks revealed why they had come to the world. A massive energy, unlike anything we had ever known, exploded into the skies. Seven great towers of light tore through the clouds. Radio signals were disrupted, planes fell from the sky, the seven seas raged.
The small towns along the sigils' lines were obliterated, flattened, erased from the world along with their inhabitants. The damage we had tried to mend after the Second World War returned in the blink of an eye when, suddenly, seven structures shook the laws of physics and corrupted the world.
The Archangels emerged, yet without God's support, they could not contain the expansion of the domains. The bodies of their angelic vessels turned to statues to create the borders between Earth and Hell.
But just a few years after the rebirth of sin, a man arose to challenge them. Satoru no Michizane was the only man to, alone, cross the borders and stare directly into the eyes of each of the seven infernal princes. He implanted seals upon each capital throne, forcing the sins to never leave their castles.
We could breathe again. Yet even so, we are not free. We are not powerful enough to kill them, nor do we know in which generation it will be possible. Therefore, do not approach our planet, even if you believe yourselves advanced enough to do so.
Flee from the planet ruled by the princes of Hell.]
The satellite carrying the message drifted through space for all eternity. By that point, it was already two hundred years away from the hopeless planet, which no longer offered safety even to its own inhabitants.