However, senses that were too sharp were not an absolute blessing.
The human mind had limits. When the amount of information being perceived was several times—dozens of times—greater than that of an ordinary person, the strain placed on one's mental faculties became an enormous burden.
So even though Nurarihyon looked anxious on the surface, in truth, Ren Kuroda's situation wasn't any better.
What Nurarihyon worried about was the excessive yōki consumption caused by repeatedly using his Fear, which might force him to revert to his aged state far sooner than expected.
Ren, on the other hand, was concerned about something else entirely: maintaining this kind of constant, passive defense was a massive drain on his mind—especially after drinking alcohol, which further dulled his combat focus and awareness.
"Spiritual Inspiration—Hidden Divine Concealment.Assassination Stance of the Honest Star…Unknowable as Yin — Lian Zhen!"
Rather than continuing to stand still and endure the pressure, Ren decided he had to do something to break the stalemate.
Among the techniques of Wind, Forest, Fire, and Mountain, none of the others would help in his current predicament.
Whether it was the lightning-fast Swift as the Wind, the overwhelmingly destructive Invade like Fire, or even the speed-and-power hybrid Move like Thunder, none of them would resolve the issue at hand.
Because no matter how fast or powerful an attack was, if you couldn't find your target, it was all meaningless.
Since he couldn't locate his opponent, and being treated like a living target wasn't exactly appealing, Ren decided he might as well fight dirty—just like his opponent.
The purple Nichirin blade slashed through empty space.
In the next instant, the space itself tore open like a stage curtain ripped apart, revealing a massive gash in the air. What followed was a scene that nearly made Nurarihyon drop his jaw.
As Ren stepped into the tear he had cut open, his body seemed to sink into an invisible curtain—then vanished completely from Nurarihyon's sight.
That's right.
Unlike Nurarihyon's Slippery Monk techniques, where the body dispersed like flowing ink, Ren didn't dissolve at all. It was as if something unseen had simply covered him, erasing his presence entirely.
In the world of yōkai, invisibility was nothing rare.
But what made Nurarihyon's expression stiffen was this—
Along with Ren's figure, his yōki and aura had vanished as well.
A living being had disappeared right in front of him, and despite Nurarihyon's countless years of experience in the yōkai world, he couldn't tell what kind of ability Ren had used, or where he had gone.
More importantly…
Why did this ability feel eerily similar to the Slippery Monk clan's Fear?
Wasn't Ren supposed to be from the Oni lineage?
Did Oni even possess this kind of Fear?
Or… was he somehow related to the Slippery Monks?
No—thinking about it carefully, Nurarihyon realized that while Ren's physical traits clearly marked him as an Oni-type yōkai, the number of Fears he possessed was simply absurd.
At first, there had been Monstrous Strength.Then, boosting yōki through alcohol consumption—both of which Nurarihyon had heard were indeed traits of Oni.
But after that came Regeneration.
And now, this ability that so closely resembled the Slippery Monks' Clear Mirror, Still Water.
Nurarihyon had never once heard of an Oni possessing such a Fear.
The battlefield, which moments ago had been filled with violent clashes, had now fallen completely silent.
Anyone unaware of the situation would never imagine that two terrifying great yōkai were lurking unseen within the air itself.
After witnessing Ren's disappearance in full—and failing to find even the slightest trace of him—Nurarihyon, hidden within the atmosphere, felt utterly stifled.
Because he realized something deeply unpleasant.
Although his yōki was stronger than Ren's, he still couldn't locate him.
All these years, it had always been the Slippery Monks using their Fear to toy with others. Never had he imagined that one day, he'd be on the receiving end of the same humiliation.
Now, both Ren and Nurarihyon had chosen to lie low.
On the surface, it seemed as if neither side would act—meaning the battle might end in a draw.
But only Nurarihyon himself knew the truth.
His current state couldn't last much longer. Once he reverted to his aged form, with drastically weakened yōki and Fear, he would have absolutely no chance against Ren.
And at the same time, Ren was thinking exactly the same thing—planning to exhaust Nurarihyon until he collapsed.
As a half-demon carrying Oni blood, Ren should, by nature, despise fighting this way. The Oni revered strength and direct confrontation.
Unknowable as Yin was a technique Ren had only ever used once before—when he'd been ambushed by that golden-glittering bastard. He hadn't used it again since.
He wanted to duel the legendary Great General of Yōkai head-on.
But the Slippery Monk's fighting style was simply too shameless.
So in the end, Ren had no choice but to play a game of hide-and-seek.
That Nurarihyon couldn't find Ren was, in truth, entirely normal.
If this were the standard version of Unknowable as Yin, then with Nurarihyon's yōki being a full tier higher, he would still be able to catch faint traces of Ren's presence—even if he couldn't pinpoint his exact location.
After all, when it came to "invisibility," the Slippery Monks were the true experts of the yōkai world.
But Ren was currently in Blade Spirit Release.
Just like how Invade like Fire — Greedy Wolf had once been empowered to the point of one-slashing a sea demon in another world, Unknowable as Yin was now drastically enhanced by the blade spirit.
While its effects were certainly not as outrageous as the Slippery Monk clan's Fear—capable of toggling between illusion and reality—when it came to concealing one's body and aura, it had unquestionably reached the pinnacle.
"…Honestly, I give up. I surrender."
After several minutes of both sides hiding within the air, a voice finally broke the silence.
"I never thought there'd come a day when I'd be defeated by a junior in this kind of way.Do you know how shameless this fighting style of yours is? As a young yōkai, you should face challenges head-on! Starting a fight and then hiding—what kind of nonsense is that?"
A tall, handsome man slowly emerged, his figure spreading into view like ink diffusing through water.
He wore a kimono and wooden geta, his hair a dazzling gold styled into a distinctive pompadour.
His looks were so refined that any woman would be instantly captivated. Beneath his eyes ran dark yōkai markings.
Elegant and charismatic at first glance—
Yet his words and mannerisms carried the unmistakable air of a street punk.
Of course, when an ugly guy acted like this, it was called "creepy."When a handsome guy did it, it was simply "bad-boy charm."
"If I remember correctly," Ren's voice echoed as he reappeared, "this so-called shameless fighting style you're talking about has always been the Slippery Monks' specialty.
"And if my memory serves me right, as the junior here, I did want to properly spar with the Great General. It's just that a certain senior kept hiding and refusing to come out, isn't that right?"