Sanemi Shinazugawa said nothing. He simply reached up and touched the faint wound on his chin.
It had been left behind when Raiden's aura surged earlier.
Strictly speaking, it was not even a real wound, more like a red mark, as if a whip had grazed his skin.
If Raiden had used that spider silk back then, would he have survived?
Sanemi asked himself the question.
The answer came almost immediately.
With his combat instincts, he might have noticed it in time, but heavy bleeding would have been unavoidable.
Sanemi looked at Raiden again, his expression complicated.
He had believed the fight escalated because he himself had not taken it seriously.
Now he realized something else entirely.
Raiden had not even used his full strength.
"I can extract Blood Demon Art from a demon's blood," Raiden said calmly after retracting the spider silk. He spoke to Kagaya Ubuyashiki directly. "There is a certain chance of failure during the extraction. This spider silk was taken from Lower Rank Five."
The truth about the system was not something he could ever reveal.
He needed an explanation that sounded reasonable, one that could both hide his secret and conveniently support Tamayo's research into demon blood.
This explanation fit perfectly.
"Extracting Blood Demon Art from a demon's blood," Kagaya repeated thoughtfully.
It sounded unbelievable, yet it was not entirely impossible.
Genya Shinazugawa, Sanemi's younger brother, could gain power by consuming demons.
Raiden was likely another special case, someone born with an unusual constitution.
As for the limits of that ability, Kagaya chose not to ask.
His relationship with Raiden was not as deep as with the Hashira, and asking too many questions would only raise unnecessary suspicion.
"You can extract Blood Demon Art from blood?" Shinobu Kocho glanced briefly at Tanjiro.
When she had rescued him earlier, she clearly remembered Tanjiro drawing blood from the spider demon's corpse using a special device.
Was that blood meant for Raiden?
Raiden waited quietly, his gaze fixed on Kagaya's clouded eyes.
He had no idea that Shinobu had already pieced together an entire scene in her mind.
"Thank you for your explanation, Raiden," Kagaya said gently. "I am very glad that the Demon Slayer Corps has gained someone like you."
"Please take Tanjiro and Raiden to receive treatment."
As Kagaya finished speaking, Shinobu raised her hand with a smile.
"Then Kamado and Raiden will stay at my mansion for now."
Kagaya nodded in agreement.
Raiden bowed slightly in response.
For now, everything was proceeding smoothly.
All that remained was to wait for the Pillar Meeting to conclude, then add the Hashira he had set his sights on.
Once that was done, this meeting would have fully served its purpose.
Raiden carried Nezuko, while two other Demon Slayer swordsmen supported Tanjiro as they departed the Ubuyashiki Estate and headed toward the Butterfly Mansion.
The mansion lay within a forest not far from the estate.
The moment Raiden stepped inside, the clean, refreshing air caused his body to relax.
The injuries from his fight with Sanemi were minor. The real issue was exhaustion.
Without the constant reinforcement of Total Concentration Breathing, he would have collapsed the moment he exited the Transparent World.
After settling Nezuko, Raiden and Tanjiro went to the room where Zenitsu and Inosuke were being treated.
This time, thanks to Raiden's intervention, neither of them had been seriously injured.
Zenitsu suffered only surface wounds, while Inosuke had a dislocated arm.
"Do I really have to drink this?" Zenitsu whined, staring at the steaming bowl of dark herbal medicine. "It's seriously bitter."
"You have asked that question eleven times already," the doctor sighed, rubbing his forehead.
The boar headed boy beside him had downed the medicine in one gulp. Compared to that, the blond boy was endlessly troublesome.
"Zenitsu?"
"Raiden!" Zenitsu's eyes lit up the moment he saw him. "Come here, hurry! I don't want to drink this stuff. I'll heal just fine, tell him!"
Seeing Raiden was like finding salvation.
After spending so much time together, waking up without Raiden around felt strange.
Still, it was good that the caretakers had explained the situation properly.
"I will handle it," Raiden said.
He took the bowl from the doctor and sat beside Zenitsu's bed.
"Raiden, I really don't want to drink it," Zenitsu said weakly, shrinking back. "It's bitter."
"How did you kill the demon on Natagumo Mountain?" Raiden asked casually.
"Oh, right, that!" Zenitsu suddenly straightened. "I figured out a new way to use Thunder Breathing First Form. I can change the attack's trajectory. Back then I was thinking…"
"Drink first," Raiden said, holding the bowl to Zenitsu's lips. "Then talk."
Zenitsu stared at the medicine, then at Raiden.
That trick again.
Raiden had always done this. No medicine, no conversation.
It was childish, and Zenitsu fell for it every single time.
Pinching his nose, Zenitsu gulped the medicine down, his face twisting in agony.
"Okay, okay," he said quickly. "So back then, I used First Form and…"
Seeing Zenitsu finally finish, Raiden leaned back against another bed and listened quietly.
Thunderclap and Flash Sixfold was a variation of the First Form.
Being able to use it meant Zenitsu's mastery of Thunderclap and Flash was nearing a critical threshold.
Raiden himself had been experimenting with variations, and after hearing Zenitsu's explanation, several lingering problems suddenly became clear.
The familiar system panel surfaced in his mind.
[Host: Raiden]
[Race: Human]
[Realm: Achieved]
[Comprehension: Superior]
[Aptitude: Superior]
[Talents: Echoing Ears, Line of Seizing, Concealment]
[Skills: Bandaging (Proficient), Thunder Breathing First Form: Thunderclap and Flash (Proficient), Thunderclap and Flash Sixfold, Second Form: Rice Spirit (Mastery), Third Form: Thunder Swarm (Mastery), Fourth Form: Distant Thunder (Mastered), Fifth Form: Heat Lightning (Mastery), Sixth Form: Electric Roar and Thunderclap (Mastered), Water Breathing First Form: Water Surface Slash (Proficient), Beast Breathing Seventh Form: Spatial Awareness (Proficient), Blood Demon Art: Sound Eating (Proficient), Blood Demon Art: Red Clean Arrow (Proficient), Blood Demon Art: Visual Dream Fragrance (Proficient), Blood Demon Art: Engraved Line Rotation (Mastery), Blood Demon Art: Dissolving Cocoon (Proficient), Transparent World (Fragment)]
[Aura: Ghost King's Aura]
Seeing Thunderclap and Flash Sixfold becoming more defined, Raiden's lips curved slightly.
Sixfold had no proficiency tier of its own. Its strength depended entirely on mastery of the First Form.
With his current aptitude and comprehension, mastering Thunderclap and Flash was only a matter of time.
Once that happened, Eightfold and even Tenfold would naturally follow.
Raiden closed his eyes and began to rest.
The Pillar Meeting would likely continue for another half hour.
He needed to recover as much as possible before then.
He would soon be dealing with Hashira level figures.
Even though it had looked like he fought Sanemi evenly, Raiden knew the truth.
Sanemi had likely not used even thirty percent of his strength.
Aside from the brief moment when the Transparent World suppressed him, Sanemi had restrained himself throughout the fight.
At first, he did not take Raiden seriously. Later, he found no opportunity to use other breathing forms.
If Sanemi had gone all out from the beginning, Raiden doubted he would have had any chance to merge with the Transparent World at all.