In the next instant—
A sharp tearing sound rang out.
The flames spiraling around Rengoku's Nichirin Blade lashed across the nurse demon's back.
Her white uniform split open along with her blood-red flesh.
Seizing the moment, Rengoku grabbed the reckless Mitsuri and retreated several steps, putting distance between them and Ryuya.
"Lord Muzan… are you alright? Did I protect you well?"
Large, scarlet tears streamed down the nurse demon's cheeks.
The warm droplets fell onto Ryuya's face, leaving him momentarily stunned.
The obsession in her eyes.
The joy and hardship tangled within her gaze.
The way she had thrown herself forward without hesitation.
And the name she murmured—
"Lord Muzan."
Combined with the nurse's uniform and her desperate act of shielding him, everything struck Ryuya deeply.
Was this… yandere love?
He could feel it clearly.
The intensity.
The longing.
The devotion that bordered on madness.
She was undoubtedly a demon—he could sense the fluctuations of her aura. A nurse in life, perhaps, who had later been turned.
But who was she?
From her reaction, she clearly knew Kibutsuji Muzan.
Yet if she were truly close to him, she would not have mistaken Ryuya for him.
Everything had happened too suddenly.
"Lord Muzan, please get up quickly! Don't be afraid! I will protect you! With me here, no one can harm you!"
Her tone rose sharply at the end, shifting into fury as she glared viciously at Rengoku.
"So scary…"
Mitsuri trembled.
The murderous intent in the demon's eyes was overwhelming—she wanted to tear them apart.
Rengoku, however, remained composed. He raised his blade upright before him.
"Retreat from the battlefield immediately," he instructed Mitsuri firmly.
"Y-Yes…"
Earlier, when Ryuya had been alone, Mitsuri thought she might be able to reach him.
Now?
With this deranged nurse demon guarding him?
She would be torn to pieces if she stayed.
And perhaps it was her imagination—but she felt the demon's hatred toward her far exceeded that directed at Rengoku.
"Anyone who dares harm Lord Muzan must die!"
The nurse shrieked.
"Your back… does it hurt?"
Ryuya slowly rose to his feet behind her.
By now, he had roughly pieced things together.
She was most likely a demon created by Muzan.
And deeply, hopelessly in love with him.
A yandere.
Besides Enmu, this was the second yandere demon Ryuya had encountered.
Enmu had been elevated to Lower Rank One largely because of his twisted devotion.
If Muzan's tastes hadn't changed, this woman's obsessive love might easily earn her a position among the Lower Ranks.
"What is your name?" Ryuya asked gently.
"Song Yue! Lord Muzan, my name is Song Yue!"
Her anger vanished instantly, replaced by shy delight.
The shift was so natural it reminded Ryuya faintly of Daki—no, of Ume.
"Song Yue… not bad. I quite like that name."
Ryuya curved his lips slightly, his rose-colored eyes meeting hers.
He called my name.
Lord Muzan likes my name.
He likes it.
Song Yue gasped softly, hands rising to her cheeks in flushed excitement.
Even after so many years, even if she could no longer perfectly recall Muzan's aura, she had never forgotten his face.
When she closed her eyes—
She saw only him.
"As long as I can be useful to Lord Muzan… I will do anything."
"Does it hurt?" Ryuya's fingers gently traced the wound on her back. His voice was soft, his gaze warm. "You were injured because of me."
Pretending to be Muzan and manipulating the situation stirred no guilt within him.
If anything—
There was a faint thrill.
"N-No, Lord Muzan! It's because I'm useless! Please don't worry about me! My wounds can heal instantly!"
Oh?
Ryuya raised a brow.
Upper Ranks could regenerate almost immediately.
Lower Ranks could not.
And Song Yue wasn't even a Lower Rank.
What confidence did she have?
As if to answer him, she suddenly sliced open her own wrist.
Crimson blood splashed outward—
And transformed midair into a white syringe.
A syringe.
So it truly was nurse-related.
Under Ryuya's watchful gaze, she seized the syringe and stabbed it into her arm.
She forced the green liquid inside into her bloodstream.
"Ah!"
Her veins bulged visibly.
Moments later, the wound on her back began to close, faint blue smoke rising as the flesh regenerated.
Medicine?
No.
Most likely her Blood Demon Art.
Lord Muzan is worried about me.
I can't disappoint him.
I must kill them.
Anyone who dares harm Lord Muzan—
Must die.
...
Author's Note:
The full completed version of Demon Slayer: Son of Muzan (Completed) is now on Patreon!
🔥 I also have additional 18+ fanfics available for readers who enjoy exclusive mature stories. 😉
1. Dragon Ball: Oolong's Sex Adventure
2. Elements of Lust – ATLA & Korra Mixed Smut
3. Doraemon: Filtering with Nobi Tamako
4. The Naive Me Who Became Someone's Everyday Secret
5. High School DxD: Rias Gremory, the Phenex Bride
6. Versatile Mage: Awakening the Succubus System
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