It was only after Yuko perfectly demonstrated every sword form of the current Snow Breathing technique that Yoriichi truly understood how difficult Snow Breathing was to cultivate.
Mixing so many different breathing styles together like this… he honestly suspected that when the Demon Slayer Corps eventually read the training manual Yuko would leave behind, they might start doubting their very existence.
Compared to the physical demands of Sun Breathing, Snow Breathing practically encompassed nearly all existing breathing techniques.
This inevitably led to one conclusion:
Most practitioners would be unable to master every form.
If they couldn't adapt to Thunder Breathing, they couldn't learn the Seventh Form.
If they couldn't adapt to Sun Breathing, they couldn't learn the Ninth Form.
Not to mention Snow Breathing itself was born from both Wind and Water Breathing—layers of requirements stacked on top of each other. It was practically impossible for anyone to master.
…
In the days that followed, the siblings trained in the mountains outside the town whenever they had time.
Under Yoriichi's guidance, Yuko improved at astonishing speed.
Even Yoriichi eventually found himself marveling at her natural talent.
He thought inwardly, "This ability of hers… may have already surpassed my brother."
Whether in breathing techniques or pure swordsmanship.
Yuko hadn't even systematically studied swordsmanship before she turned eighteen.
Back when she was with the Demon Slayer Corps, Yoriichi was often away, and there were many others who needed teaching—he never really spent much time training her personally.
Now, he finally had the time to do so.
And after she became a demon, her only weakness—
that of being physically inferior due to being a woman—
had been effortlessly resolved.
In pure combat power, women were naturally weaker than men.
But now, Yuko could create a crimson blade with ease thanks to her demon strength.
Though ironically, whenever she looked at the crimson blade in her hand, she herself was the one most frightened by it.
There was no denying it: she had indeed gotten stronger.
Their battles in the mountains gradually began to draw the attention of passing travelers.
Rumors spread throughout the town that during that period, the God of Fire and the God of the Moon were fighting in the mountains outside town.
Some claimed to have seen a silver full moon fall from the sky.
Others swore they had seen blazing flames ignite the horizon.
No one believed it at first.
But some decided to investigate, and upon seeing the countless inhuman battle marks scattered through the dense forest, they were frightened into illness.
The mountains outside town slowly became viewed as a forbidden zone—no one dared enter lightly.
As the rumors grew increasingly outrageous, Yuko and Yoriichi became more cautious.
From what Yuko had observed, the strength level of this world, compared to novels from her previous life, at best counted as a "high-martial" world.
Even someone as strong as Yoriichi—if he stayed still, a child with a knife could stab him to death.
His physical body was far weaker than hers now, which rivaled steel.
In terms of physical strength and power of sword techniques, she was clearly superior.
But Yoriichi always defeated her through sheer overwhelming speed.
His ability to execute all twelve forms of Sun Breathing in an instant was something even Yuko could not fully see now—and no wonder Muzan had doubted life itself upon witnessing it.
It truly embodied the saying:
"In all martial arts under heaven, speed is undefeatable."
…
After training, the siblings lay in the quiet forest. The insects and beasts that once lived there had long disappeared.
As summer arrived, Yuko said, "Brother, I want to visit Sumiyoshi's family soon."
"…Mm." Yoriichi blinked, then answered softly.
"You should come too."
"…"
Yuko sat up and looked at him with a teasing half-smile.
"Brother… you're not embarrassed to go back because last time you were too formal, right?"
Giving earrings, performing sword forms—
All very ceremonious.
Yoriichi: "…"
Seeing him remain silent, Yuko narrowed her eyes thoughtfully.
"If you don't go, and I… accidentally lose control…"
"…I'll go."
Yuko smiled faintly.
This open scheme—let's see him try to refuse!
Although Yoriichi trusted Yuko, demons were unreasonable, inhuman creatures.
He wouldn't doubt it if someday she truly lost control. It wouldn't be her fault.
Humans had extraordinary willpower, but some things simply could not be resisted through will alone.
…
When Sumiyoshi's family saw Yoriichi and Yuko again, they were overjoyed.
Yoriichi seemed to have untied the knot in his heart—
he smiled more often now.
Sumiyoshi was happy for a long time because of this.
During their previous visit, Yuko had speculated that the Blue Spider Lily bloomed in summer.
This time, she found it.
On an August night, she stared at the grave of Uta for an entire night and saw no flowers.
During the day, she had Yoriichi go keep watch.
He didn't understand her intention, but he obediently stayed until two in the afternoon—
the day's hottest moment—
and discovered the suddenly blooming flower.
"Ah~"
When Yoriichi picked the Blue Spider Lily and brought it to Yuko, curious about what she intended—
Yuko opened her monstrous mouth wide and ate the flower raw on the spot.
Sumiyoshi's family: "…"
Yoriichi: "…"
Licking her lips, Yuko commented, "It tastes bad."
!!!
Of course it does! It wasn't even cooked!
Everyone's pupils trembled violently.
Yoriichi frowned slightly. "So… what exactly is it?"
Yuko answered seriously, "It seems Muzan has been searching for this. It might be something that allows demons to overcome sunlight."
Yoriichi's eyes narrowed.
"Overcome… sunlight?"
Yuko sat inside the house and extended a finger directly into the sunlight.
Szzzt—
She withdrew her hand without changing expression.
The flesh regenerated instantly.
She murmured, "I'm sure. It might require a certain amount… a buildup."
Suyako stared in shock at her fully restored finger, then hesitated.
"I think… I sometimes see that flower behind the house."
"Yes, it blooms behind the house. It should only bloom in summer."
"I think so too—we even cooked it as wild vegetables once." she recalled.
Sumiyoshi's expression darkened, and he spoke seriously:
"If it can really let the Demon King overcome sunlight… shouldn't we use it as bait to lure him out?"
Yuko and Yoriichi both shook their heads immediately.
Yuko sighed helplessly.
"That guy is extremely cautious. Especially since Yoriichi might still be alive, he absolutely won't appear in person."
"It would only alert him."
Suyako suddenly stood up and grabbed a hoe.
Everyone stared.
"If we just destroy the flowers, then we won't have to worry about demons finding them, right?"
"That way, he'll never overcome sunlight."
You're way too smart.
Yuko mentally groaned and hurriedly stopped her.
"Wait, Suyako!"
If she actually destroyed them, Muzan might truly never be defeated.
Nezuko is the protagonist's little sister!
Apart from Tamayo, she's the only demon who breaks free from Muzan's control.
Who knows—
by the final battle she probably needs to tag-team with Tanjiro to beat Muzan!
---
Currently at chapter 207 for advance chapters
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