The World Battlefield is a separate, isolated dimension where the powerful fighters of the New World, formed from the fusion of three worlds, clash with enemies from other worlds.
This battlefield operates under a unique rule: balance. Within this space, the upper limit of combat strength between the New World and the Otherworld is always kept equal.
The key to breaking that balance lies with the New World.
For instance, if the New World sends one of its top fifteen fighters onto the World Battlefield, then the number of SSS-ranked fighters allowed there is limited to two, one from the New World and one from the Otherworld.
Likewise, if the New World deploys two of its top fifteen fighters, the number of SSS-ranked fighters on the battlefield is capped at four, allowing the Otherworld to field two SSS fighters as well.
There is no doubt this rule favors the New World. After all, the Otherworld far surpasses it in the number of powerful fighters. Without this restriction, the New World would not have been able to hold out for over a year.
But that is where the advantage ends. This cap on combat strength can only go up, never down.
If the New World deploys three top fifteen fighters, and one of its SSS fighters is injured and forced to withdraw for recovery, or is killed, the cap on SSS fighters still remains at three.
The Otherworld's limit will not drop from three to two because of that. It will stay at three.
And if no one can step in to fill that missing top fifteen position, then two top fifteen fighters facing three SSS-class opponents, the outcome is obvious.
This is an inherently unfair war of attrition. On one side, the Otherworld can immediately replace fallen fighters with fresh powerhouses. On the other, the New World must deal with injuries and rotate its forces, similar to the eternal war between the gods in High School DxD and 666.
Under normal circumstances, no one would even realize this rule exists. It was only after prolonged fighting between the New World and the Otherworld that people began to suspect it and eventually confirmed it.
In most cases, when a normal world is invaded by the Otherworld, that world, capable of gathering most of its strength, would without hesitation mobilize nearly all its forces and send them straight to the World Battlefield.
But doing so would push the battlefield's upper limit of power to a level that makes sustainable rotation impossible. In the end, there is a 99 percent chance that world would be overwhelmed by the Otherworld's numbers, as its losses would outpace its ability to recover.
The reason the New World discovered this rule is somewhat ironic.
Each faction feared that if they committed all their strongest fighters, the other two worlds might stab them in the back. So unless absolutely necessary, they refused to send even a single powerhouse to the World Battlefield.
It is understandable. To the people of each world, the other two fused worlds were no different from the Otherworld. They were all outsiders.
And through this strange coincidence, someone finally uncovered the balancing rule of the World Battlefield.
The Dimensional Gap was where the World Battlefield first appeared. The current separate space where the New World fights the Otherworld is the second stage.
Right after the three worlds fused, when their strongest beings had only just realized what had happened, what arrived sooner than the hostility and conflict they feared from the other two worlds was a wave of energy surging out from the Dimensional Gap, striking the Human Realm, the Underworld, Olympus, Yggdrasil, and other realms connected to the human world.
Some of the top experts from World One quickly realized what was happening. A Dragon God-level being was battling the Great Red. These indiscriminate energy blasts were simply the aftershocks of that clash.
In just a few minutes, these waves of energy from the Dimensional Gap caused heavy losses across all factions.
Worse still, the attacks did not stop after those first few minutes. Instead, their frequency doubled.
It was not until the Great Red left the Dimensional Gap and threw the World Battlefield into the New World that this disaster finally subsided. Even so, energy shocks would still occasionally erupt from the Dimensional Gap, striking different factions at random.
Later, after investigation by some of the top fifteen fighters, it was determined that these energy shocks were the residual effects of the Great Red pursuing and attacking two other Dragon God-level dragons.
After discovering the balancing rule of the World Battlefield, and considering that the battlefield itself had been thrown out of the Dimensional Gap by the Great Red, it did not take long for people to deduce that the two dragons came from another world.
Three attacks, each a different color and each powerful enough to instantly kill a top fifteen fighter, shot in from three different directions at the venue drifting within the Dimensional Gap.
Faced with the incoming attacks, the powerful figures inside the venue snapped out of the daze caused by the earlier dragon roar.
Now, they had been targeted by the three dragons because of the Samael aura lingering on them.
Like a sail caught in a violent storm, the venue shifted abruptly under the joint control of those present, narrowly redirecting itself so that the three world-shattering attacks collided with each other. The resulting surge of Magical Power slammed into the venue and sent it hurtling away.
Giada raised her head and, for the first time, saw the legendary Great Red.
Crimson scales covered its entire body. Despite its immense size, it did not appear bloated. Its streamlined form carried a sense of elegance, while its physique displayed the overwhelming strength of the Dragon race. A dragon born from dreams, the Great Red, known to the world as the [True Red Dragon God Emperor].
After just a glance, Giada shifted her gaze toward the sources of the other two attacks.
Why must the New World fight the Otherworld? Are not the other two worlds that merged with it also "other worlds"?
A massive skeletal dragon, devoid of flesh, its bones so pale they sent chills down one's spine. In its hollow eye sockets burned eerie purple soul flames, and it flapped a pair of skeletal wings that clearly could not sustain flight.
Because…
Chunks of rotting flesh fell away like crumbling concrete, only for the missing parts to regrow instantly. White fuzz sprouted between its scales, and within the torn flesh of its body crawled countless black insects, so dense they made one's skin crawl. This was a zombie dragon.
No one wanted to become something like that.
The so-called Otherworld was nothing more than a dead world, one that had lost all life and could only survive by plundering the life of other worlds.
How could a world that had already lost all vitality produce creatures like these, a bone dragon and a rotting dragon capable of standing against the Great Red?
No one knew, and no one dared to find out.
Seeing the shockwave from the three colliding attacks send the venue flying, the Great Red, flapping its crimson wings as it moved through the Dimensional Gap, paused and looked toward the origins of the other two attacks.
Only then did he realize that the two Evil Dragons from another world he had been pursuing had also been drawn here by the aura of the Dragon Eater.
"Roar!!!"
A roar filled with unmistakable excitement erupted from the Great Red's throat. A dreamlike crimson mist spread out, enveloping the two Evil Dragons and the venue suspended in the air.
Over the past year and more of pursuit, he had encountered one or the other of these Evil Dragons several times, yet each time they had slipped away.
But now, the two Evil Dragons were far too close.
So close that there was no chance he would let them escape.
This time, they would not get away.
Crimson Magical Power gathered in the Great Red's mouth. After a few seconds of charging, it burst forth, an ocean-like torrent of power sweeping toward the two Evil Dragons.
Twisting their grotesque bodies and realizing they could not break free from the crimson mist, the two Evil Dragons opened their mouths as well. White-gray and dark green Magical Power surged out, blasting indiscriminately in all directions.
Their targets were not only the Great Red, but also the other invading Evil Dragons… and even the Underworld venue.
This was what enemies from a world that had lost control of its battlefield looked like. They still retained the instinct to seek advantage and avoid danger, but they had no real awareness. Unable to distinguish friend from foe, they attacked everything indiscriminately.
"Boom!"
Once again, the venue barely managed to avoid the collision of the three Dragon God-level attacks. Even so, everyone inside suffered varying degrees of injury from the aftermath of their clash.
The three Dragon Gods were not deliberately targeting them. To beings at that level, they posed no real threat. But because of the lingering aura of Samael, they had no reason to avoid dragging them into the battlefield either.
"Phew…"
Watching another attack aimed at the Great Red sweep them into its range, several of the powerhouses inside the venue let out quiet sighs.
It seemed there was no saving their subordinates. The venue itself was already on the verge of collapse. From here on, it would be every man for himself.
Even among the top fifteen, one or two would likely die here.
At that moment, a purple Magical Power barrier appeared out of nowhere and blocked the incoming attack. A blue-violet surge of power tore through the Great Red's crimson mist, and the sudden presence that emerged caused all three Dragon Gods to halt mid-battle.
"I am quite satisfied with this invitation to the ball."
Seated at the very top of the venue, a black figure casually swirled a glass of red wine, a wild grin visible beneath the mask.
"Come, let's have a dance. Let's finish the battle that should have ended over a year ago."
Raising his glass toward the void, Cid extended his invitation to the three Dragon Gods before him.