Since the last three-party war in the biblical pantheon, the God of the Bible, the four Demon Kings, and the twelve-winged governors of the fallen angels were all killed.
Whether it was the underworld, heaven, the human world, or other worlds of gods, all were caught in a delicate balance. No one was willing to break this balance and start a war. The reason was simple: after the death of the God of the Bible, heaven could no longer give birth to pure angels.
In the underworld, half of the demonic families were wiped out, leaving no heirs to continue their bloodlines. The remaining families struggled with difficulties in producing pure-blooded demons. The fallen angels were similarly devastated, with most of their middle and lower ranks wiped out, leaving only a few twelve-winged fallen angels who struggled to survive.
With continuation unsustainable, the three factions shared an unspoken understanding, each fearing that starting another war would lead to their total annihilation. Without official peace negotiations, they still carefully maintained a fragile balance. All three sides were desperate to avoid a war that would bring about their complete extinction.
For this reason, all three factions pinned their hopes on the humans in the human world. Humans, by nature, were beings of miracles. Their faith could empower gods, and they could even be perfectly reincarnated as demons, fallen angels, or angels. This caused all three sides to turn their attention to the human world, relying on tacit agreements and competition to recruit outstanding humans to join their camps.
Of course, this was only on the surface. It was not uncommon for one side to secretly take advantage of exceptional humans who had joined the opposing camp. After the death of the God of the Bible, a bug appeared in the "system" belonging to the biblical pantheon. The "miracles" originally reserved only for believers were now distributed to all of humanity without distinction. These "miracles" were sacred relics—even god-slaying tools capable of annihilating gods and demon kings.
The demon families of the underworld and the fallen angels gave the highest priority to recruiting humans who possessed these "sacred relics." In response, the four Demon Kings created demon chess pieces capable of easily transforming humans into devils to bolster the underworld's forces.
Originally, everything seemed to be proceeding peacefully. The four Demon Kings, having managed to stabilize the underworld, began to enjoy a semblance of comfort. But unexpectedly, a sudden crisis enveloped the entire underworld.
The "underworld" began to shake violently, with space-time faults even appearing near the "edge of the world." A space-time fault was a catastrophic event that threatened the entire world—not just the underworld, but all other realms as well.
At the Gremory estate, Sirzechs Lucifer, the current Demon King and the one who inherited the title of "Lucifer," was working diligently when the shaking began. His gentle expression turned grim as he sensed the disturbance. He immediately stood up, his chair falling over.
"The underworld is shaking! Space-time faults at the boundary—what is happening?" As the strongest figure in the underworld and someone who had surpassed his predecessor Lucifer, Sirzechs could feel the aura that enveloped the underworld. It was an aura foreign to their world.
"Something is happening beyond the world… in the dimensional gap?" he wondered aloud, his heart heavy.
The external force affecting the world was unlike anything recorded in ancient texts—even the great tomes from the past. "Could it be… the Great Red?"
A crimson magic circle appeared under his feet, and in an instant, Sirzechs vanished from the estate, reappearing at the boundary of the underworld—the world's membrane.
"What?" Sirzechs was taken aback at the sight before him. The "world membrane" was in a constant state of distortion and restoration, causing time and space to break and repair themselves. An immensely terrifying aura poured into the underworld from the twisted world membrane. Even the highest-level demons would be instantly obliterated if caught in its proximity.
Moments later, three more magic arrays appeared, and the other three Demon Kings emerged. The young girl with waist-length black hair tied into twin tails, who had a lively yet stern demeanor, frowned, sweat forming on her forehead. She was Serafall Leviathan, one of the four Demon Kings.
"Sirzechs, what's happening? Why is the world's boundary like this?" she asked, her voice trembling.
Sirzechs responded solemnly, "I don't know. The entire underworld began shaking suddenly, and it's clearly linked to something happening outside the world."
Ajuka Beelzebub, another Demon King, added with concern, "Something is happening beyond the world. There's nothing else in the dimensional gap except the Great Red and Ophis, the Infinite Dragon God. Could they be fighting?"
Falbium Asmodeus, the fourth Demon King, held his head, panic evident in his eyes. "Are you serious? I haven't even finished preparing for my vacation yet. If those two dragon gods are really fighting, we're in deep trouble."
Sirzechs tried to calm his fellow Demon Kings. "We can't be sure it's the two dragon gods. Even if they were fighting, it shouldn't have caused this level of disturbance. A space-time fault means the entire world is being affected."
Ajuka nodded. "We need to understand what's happening in the dimensional gap immediately."
Sirzechs took a deep breath. "That's why I was about to open a hole and see for myself."
With that, Sirzechs opened a small hole in the world membrane in front of him. Instantly, the aura, suffocating in its intensity, poured into the underworld.
"Get back!" Ajuka shouted, his face filled with horror.
In that brief moment, Sirzechs caught a glimpse of a cataclysmic battle within the dimensional gap. It was as if they were ordinary people struck by a high-speed train, and they were instantly hurled backward by the force of the aura.
Rumble, rumble—
The floating mountains on the edge of the underworld were impacted by the four Demon Kings, shattering unknown peaks. The aftermath wasn't limited to them. The massive aura that entered the underworld crushed the surrounding mountains, with the debris forming a meteor shower as it hurtled further inward.
The underworld wasn't the only realm experiencing this event. Heaven, Takamagahara, Olympus, the Celtic God Realm, and Asgard—all these divine realms shook in response to the overwhelming power breaching the dimensional gap.