On the exorcists' side of Tokyo's districts, Yuto had been classified as an SS-rank yokai from the very beginning. Because of that assumption, all of their preparations had been made according to the standards required to deal with an SS-class monster.
Later, when they discovered that Yuto's actual level was only S+, falling short of the SS rank they had anticipated, they had even felt a small measure of relief.
But after truly engaging him in battle, they finally understood something terrifying.
Although this oni-type yokai's yokai power was "only" at the S+ level, his overall threat was absolutely on par with a genuine SS-class monster.
The fact that he had survived the old S-rank Fire-Swarm family head's suicidal spiritual detonation was no coincidence at all.
Even after being locked in prolonged combat for so long, with their side having already revealed nearly all of their trump cards, they still hadn't figured out how many other tricks this monster might be hiding.
Swordsmanship. Storms. Monstrous strength. Flames. And now this barrier-like domain, along with a power capable of breaking seals.
What ordinary yokai could possibly possess such an absurd variety of abilities?
After hearing the head of the Kagamori family speak, Kusu Ryosuke no longer hesitated. Relying on his exceptional perception, he instantly pinpointed Yuto's position within the darkness, gripping the Kusanagi Sword as he charged straight at him.
Yet now, when facing Kusu Ryosuke's assault, Yuto had no intention of entangling himself in a direct clash. Instead, he rapidly evaded through the darkness.
Yuto wasn't an idiot.
With his yokai power still sealed, going head-on against Kusu Ryosuke would have been nothing short of suicidal.
Although the power of "All the Evils of This World" could indeed corrode the seals binding him, Yuto feared that drawing too much of that force would cause him to lose control and fall into a blackened rampage. Because of that, he had restrained himself from using it excessively.
The pitch-black, mud-like mass of "All the Evils of This World" clinging to him was still relatively small. While it was eroding the seals, the process wasn't particularly fast.
Both Yuto and Kusu Ryosuke were top-tier masters of the sword. Beyond having awakened Mind's Eye, their five senses had long since surpassed those of ordinary humans. As a result, the pitch-black environment barely affected either of them at all.
Within the darkness, Kusu Ryosuke, as the attacker, pressed Yuto relentlessly, step by step. Yuto, meanwhile, fought in constant motion, weaving and circling rather than confronting him directly.
He wrapped the blade of Oni-Wound in yokai power, ensuring it wouldn't shatter under the pressure of colliding with a divine artifact like the Kusanagi Sword.
Judging purely by swordsmanship, Yuto was actually superior to Kusu Ryosuke. But with the amplification provided by the Kusanagi Sword, every time their blades clashed, it was Yuto who ended up at a disadvantage.
As time passed, more and more wounds appeared on Yuto's body, leaving him looking thoroughly battered.
Yet despite having completely suppressed Yuto with the Kusanagi Sword, Kusu Ryosuke showed not even the slightest trace of joy on his face.
Because although he could clearly feel that the oni yokai before him was being pushed back under his attacks, he hadn't managed to inflict any truly devastating injuries from start to finish.
Moreover, while Yuto's wounds were increasing in number, Kusu Ryosuke could keenly sense that Yuto's breathing wasn't even slightly disordered—and that the yokai power within his body was steadily growing stronger.
No… "stronger" wasn't quite the right word.
It would be more accurate to say that Yuto was gradually breaking free from the seals restraining him, steadily restoring the yokai power he had possessed at his peak.
The most obvious sign of this was the shifting battle situation.
What had begun as Kusu Ryosuke completely suppressing Yuto gradually evolved into an evenly matched exchange—and then, little by little, into Yuto reclaiming the upper hand.
When Kusu Ryosuke realized that the tide had turned yet again, a wave of helplessness surged through him.
Even when the enemy had been at his weakest, he hadn't been able to deal a decisive blow. Now that Yuto was steadily shaking off the seals, his chances of victory were becoming vanishingly small.
After breaking free from two layers of sealing, the yokai power surging from Yuto's body had already returned to the S+ level.
Though he had suffered quite a few injuries in the process, the disappearance of the seals—like heavy shackles being lifted from his body—left him feeling immensely relieved. He shifted from defense to offense, gradually forcing Kusu Ryosuke back instead.
In the darkness, after clashing with Yuto once more and once again falling into a disadvantage, Kusu Ryosuke understood that if the fight continued at this pace, defeat was inevitable.
After a moment of hesitation, he chose to gamble on a dangerous, desperate move.
Before the Kusanagi Sword truly acknowledged its master, the power it could wield was limited. The divine energy it contained had been stored over countless ages.
Although Kusu Ryosuke's abilities were currently enhanced across the board, those boosts weren't permanent. Once the Kusanagi Sword's stored spiritual power was exhausted, even a divine artifact would be little more than an exceptionally sharp and durable weapon.
Realizing this, Kusu Ryosuke concluded that a prolonged battle would be extremely unfavorable to him.
And so, in the depths of the darkness, he actually released his grip on the Kusanagi Sword—then drew his own personal blade once more: Ōdenta Mitsuyo.
At this moment, Yuto had completely broken free from all three layers of sealing. His yokai power had returned to its absolute peak.
He could also sense that Kusu Ryosuke was nearing his limit. At this rate, another few dozen exchanges would surely end in his opponent's defeat.
Within the endless darkness, after locking onto each other's positions, the two once again charged forward at blinding speed. Collisions like this had already occurred several times before.
The outcome, however, had shifted—from Kusu Ryosuke holding the advantage at first, to Yuto now clearly dominating.
"Claaang—!"
The piercing clash of metal echoed through the silent darkness as a violent storm erupted outward. The ground beneath their feet caved in instantly, forming a massive crater from the sheer force of impact.
Yet this collision was nothing like the previous evenly matched clashes.
After only a brief moment of stalemate, it ended with Kusu Ryosuke vomiting blood and being hurled backward.
The result left even Yuto stunned.
In their earlier clashes, even when Kusu Ryosuke had failed to gain the upper hand, he had never been defeated so completely.
And if Yuto hadn't misjudged it, the blade that had just collided with Oni-Wound hadn't been the divine Kusanagi Sword at all—but Kusu Ryosuke's own weapon, Ōdenta Mitsuyo.
The instant Yuto sensed something was wrong, a powerful feeling of danger exploded behind him.
It was a sense of crisis so intense it carried the unmistakable stench of death, making even his skin tremble.
Divine Power of the Kusanagi Sword: Fire-Quelling Sacred Relic—Flying blade unsheathed, disaster averted!
According to legend, when Yamato Takeru faced mortal danger, the Kusanagi Sword had leapt from its scabbard on its own, cutting down all the surrounding withered grass. This was proof that the sword possessed the ability to attack of its own will.
Moments earlier, Kusu Ryosuke had deliberately released the Kusanagi Sword, leaving it hidden within the darkness, while he himself clashed head-on with Yuto using Ōdenta Mitsuyo.
The outcome unfolded exactly as he had predicted.
Believing that Kusu Ryosuke still wielded the Kusanagi Sword, Yuto collided with him once more. Deprived of the divine blade, Kusu Ryosuke was grievously injured—so badly that he could no longer continue fighting.
But because Yuto had overlooked the Kusanagi Sword lurking in the darkness, he had exposed a massive opening after that clash.
And now, that opening was the perfect chance to finish him.
The Kusanagi Sword, which had been lying in wait within the darkness, suddenly transformed into a bolt of lightning. Before Yuto could even react, it shot straight toward his heart.
This time, the Kusanagi Sword seemed almost conscious, no longer sparing its stored power. It unleashed every last drop of divine energy within its blade, erupting with blinding radiance as it thrust forth its strongest strike.
In the darkness, the Kusanagi Sword burst forth with unprecedented brilliance. Even the pitch-black innate domain was illuminated as brightly as day.
Along the blade, phantom images appeared—the shadow of an eight-headed serpent,the figure of a man standing atop a serpent's body with sword raised high,and the image of an armored warrior cleaving through flames with a single swing.
All of these phantoms converged, merging into a single streak of light along the sword's edge—like a comet tearing through the night as it hurtled straight toward Yuto.
The overwhelming sense of danger crashed down upon him.
Thanks to Yuto's exceptional Mind's Eye, as well as the heightened senses he had cultivated through swordsmanship, he had foreseen the threat a split second in advance.
But even with that foresight, the clash with Kusu Ryosuke had left his body locked in rigid recovery.
Simply forcing himself to turn around strained his coordination to the limit—dodging was utterly impossible.
And with the Kusanagi Sword having charged for so long, its explosive speed left Yuto with no room to evade at all.
Pouring every ounce of his yokai power into Oni-Wound, Yuto stared at the comet-like blade streaking toward him and chose the only option left—
to face it head-on.
"BOOOOOOM—!"
A thunderous explosion shook the world.
The surrounding ground collapsed in massive sections, as if struck by a calamity-level earthquake.
Even the five great family heads lying scattered in different corners could feel the terrifying surge of spiritual power crashing through the barrier.
A bowl-shaped halo of energy spread across their vision in an instant, followed by a colossal storm that swept away everything in its path.
Seeing the horrifying power unleashed by the divine Kusanagi Sword, the expressions on the faces of the five family heads finally relaxed, relief washing over them.
"Taking an attack like that from the Kusanagi Sword while completely unguarded… no matter how many tricks that monster has, no matter how much it defies common sense, there's no way it could have survived."
"This victory really is thanks to Head Kusu's decisive judgment. To think he'd even use himself as bait at the end, just to create that opening for the Kusanagi Sword…"
After the massive explosion subsided, the darkness surrounding them began to recede.
And that only reinforced the belief of the family heads—
that the enemy had surely perished in that final, devastating strike.