Lower Rank One and the successfull trap

'Why didn't you use Bankai in your fight with the demon on the cliff?' Kai had asked Shinobu a few days ago.

This question had been popping up in his mind for a long time. Especially after learning about Bankai, it made even less sense to him that the Insect Hashira had been beaten to a pulp by that demon.

And sure enough, it turned out that Kai had assessed the situation, while spying on them, correctly.

Shinobu had been ambushed, and not by a low-class demon.

Before arriving in the mountainous region, Insect Hashira had been commanded to lead Zenitsu and Inosuke in search of Kai, with Giyu and Tanjiro making a second team. At some point, Shinobu separated her team into two groups, with the newbie demon slayers making one and herself another.

It was then she had sensed the foul presence of strong demons.

While pursuing the said clue, she had come face to face with a white half-hand, having a mouth and an eye, at that cliff, who sent her to sleep instantaneously.

Recalling her experience, and depending on her astute instincts and analyzing skills, Shinobu had concluded a few points about that encounter and this demon's Blood Demon Art. Not to mention, her Sword Spirit had helped her in painting a clear picture of the situation as well.

First, according to the Insect Hashira, this particular demon could force anyone into a deep sleep.

Second, the demon could enter, manipulate, and control dreams. He could make his victims experience joyous dreams, suited to each person, taking advantage of their vulnerabilities and ensuring they could not differentiate dreams from reality, thus rapidly seducing them to embrace the Utopian visions that lay before them.

From her experience, Shinobu had told Kai that the dreams were too lifelike, and she had almost wished to not realize their falseness. She had also guessed that the demon could induce nightmares, too, despite not having them in her dreams.

Third, and the most fatal, was the fact that the demon could enter the dreamer's mind. This dream realm had clear limits with boundaries, beyond which lay a person's subconsciousness, or the Inner World. This Inner World housed the Spiritual Core of a person, and for the Demon Slayers, their Sword Spirit as well. The demon could enter this Inner World, without letting the dreamer know about it, and destroy the Spiritual core, destroying the dreamer's mind along with it.

In her case, the demon had indeed entered her Inner World hoping to destroy her Spiritual Core but got thwarted by her Sword Spirit. From what her Sword Spirit had told her, they were evenly matched in the Inner World, making Shinobu guess the demon was at least a Lower Rank One or Two from the Twelve Kizuki, an elite force under the King of Demons.

However, the said fight between the demon and her Sword Spirit in her Inner World was nothing but a stalling technique. By the time Shinobu had figured out a way to leave the forced dream, an Upper Rank Demon had already dealt a fatal blow to her vitals.

No wonder she couldn't awaken the Demon Slayer Marks and resonate them with each other to release her Bankai. She had been fighting two battles simultaneously, one outside and the other in her Inner World, using her Sword Spirit.

When Kai had come, this dream demon had been forced to leave Shinobu's Sword Spirit, but things had already become unsalvageable by then.

Her death was an outcome set in stone if Kai hadn't come to save her, and the further treatment he had given to her in the hut.

Coming back to the present, Kai saw the boy smiling at him, but his eyes weren't reflecting the boy's image. It was the hand propped up on the boy's shoulder. This hand was cut just above the wrist, looked pale and white, and there was a mouth on the backside of its palm. To the right of this mouth, over the thumb, was a green toad-like eye. [Image 1]

Kai's hair stood over his neck as he saw the mouth open, rows of bone-white teeth salivating over the boy's shoulder.

It was the same dream demon.

The realization struck him like a bolt of lightning. Behind him, he could feel Nezuko running towards Shinobu. If they fell to sleep now, it was all over for them, Kai knew.

A red-green tongue slithered out of the mouth on demon's hand and licked its teeth, and said, "Go to…"

Kai's webbed hands lifted along with the first two words, and as the mouth uttered the last word, he slammed his flat palms over his ears.

"… sleep!"

Whispers of Forced Unconscious Hypnosis! [GIF 1]

The spell caused a formless shockwave to explode out of the mouth, directing it towards Kai and Nezuko.

However, it was also the time when Kai's palms landed on his ears.

Smack!

Kai had no way to tell if this dream spell's origin lay in sound waves, Mana, or Breath. But, from what he had learned from Shinobu, he could surmise that listening to the words spoken by the mouth was the core of the demon's trick.

And Kai had always been a decisive person, even in extreme and hazardous situations. He wouldn't have survived the onslaught of an entire world in his previous life otherwise.

Blood burst from his ears, his smack rupturing his eardrums. A ring buzzed in his mind, and the world shook, rotating, revolving in his eyes. Kai gritted his teeth in anger and pain and somehow prevented himself from losing his balance.

A tiny, sudden drop in HP was of no concern to Kai. The ruptured eardrums would heal in a few minutes, he knew. Before that, he must take care of this demon.

Advance Telekinesis burst out with fury about it, and sent the boy and the hand slamming into the wall behind them. The boy was a normal human child, and he lost consciousness after the impact. The mouth on the hand clacked its teeth and ran away on its fingers.

Kai didn't pursue it. He spun and saw Nezuko lying on the floor. The dream spell had hit her head-on, making her sleep. Kai grabbed the package by the neck, stuffed it into the wooden box, and put the box on his back.

Then he ran to Shinobu, who was sleeping as well, her brows furrowed and pressed together in deep struggle. Kai slapped her a few times, but when he didn't see her waking up, he lifted her in one arm. In the other, he was already wielding Murasame.

'I must leave this inn first,' Kai reasoned. 'Who knows where the rest of the demon's body is hiding? Tch!'

So Kai spun around once more, running inside the room. Obviously, the easiest and shortest way out of the inn was through the window.

The window was just a few feet away from him now. He could even see the sheet of rain beating against it, and the unheard roars of thunders lighting up the dark sky. One more moment, and he would be out of the inn.

'Hmm?' A sudden thought bubbled up in his mind. 'This?! Isn't this just too easy?'

Kai's head was just inches away from the glass.

It was then his instincts went wild. 'Not good!'

Too late.

The window, which had an ordinary appearance until now, suddenly opened by itself like the parting of eyelids over an eye. No. It Was an eye.

The entire window had become a gigantic eye with strange characters embedded in its pupil.

Kai wasn't all-knowing, and neither was Shinobu. How could they have known, or even imagined, that just speaking out with a mouth on its hand wasn't the demon's true power?

The same formless shockwave, but with even more intensity, exploded out of the eye. Its target? Kai.

Eyes of Forced Unconscious Sleep! [GIF 2]

He knew what he must do now. In that tiny moment, Kai's brilliant mind had already figured out that he must blind himself. Alas! His Agility wasn't high enough for such a tremendous reflex. Nor could he shut his eyes in time.

Kai's entire figure wavered as if a powerful gust of wind had hit him on the face, his eyes rolling back into his head.

With a dull thud, both Kai and Shinobu fell to the floor, their eyes fluttering, their minds lost in the realm of dreams.

No matter if it was because of the pounding headache dulling his instincts, or the dizziness caused by the rupture of his eardrums, Blood Demon had finally fallen into a brilliantly laid trap.

Even Selene couldn't help him now.

She, herself, had been dreaming about Kai patting her head and kicking Item-M, Cersei, and Petyr since a while ago.