The phenomenon of the Mark often worked such that when one swordsman awakened it, it would subtly influence nearby swordsmen, causing those capable of awakening the Mark to do so unconsciously.
At this moment, Haku found himself in such a situation.
Nezuko's unexpected awakening of her Mark had affected him, stirring the potential within his body, already honed by Water Breathing.
Thanks to his chakra, Haku's control over his body far surpassed that of the Demon Slayer Corps' swordsmen. He quickly determined that this stirring power was not harmful, so he stopped suppressing it, allowing Water Breathing to fully unleash the Mark's power.
In an instant, a scar-like Mark appeared on Haku's face, though hidden beneath his dog-faced mask, unnoticed by others.
With the Mark awakened, Haku's speed and strength surged dramatically.
The tide of battle reversed in a heartbeat!
In the distance, the trainers and swordsmiths were dumbfounded.
"How is this possible!?"
"Even Nezuko in her Mark state can't overpower that kid?"
"Suppressing Sun Breathing with Water Breathing is already unbelievable, but to overpower Nezuko with her Mark awakened? Where did Urokodaki find this monster?!"
Not only them, but the dozen-plus swordsmen Haku had defeated were also watching this peak clash from afar.
When Nezuko awakened her Mark, many thought the battle was over. Yet, in mere minutes, Haku had turned the tables, regaining the upper hand.
On the cliff, a piercing metallic clash rang out.
Clang.
A Nichirin Blade was sent flying, spinning through the air before landing on the ground.
The next moment, Haku's blade rested at Nezuko's neck. "You've lost."
Nezuko, panting heavily, looked dazed, as if unable to comprehend her defeat.
Haku glanced at the Mark on her face and sighed softly.
Having awakened his own Mark, he had figured out what it was and what it meant.
In simple terms, the Mark was a swordsman's way of pushing their body beyond its limits through Breathing Styles.
The difference was that swordsmen like Nezuko, native to the Demon Slayer world, lacked chakra or other special energies. Their only means of pushing themselves was to burn their life force, which often made Marked swordsmen short-lived.
Haku, however, was different. With chakra, he could sustain the Mark state by expending chakra instead. His Mark was merely a fusion of Water Breathing and chakra, meaning it wouldn't shorten his lifespan.
With Nezuko, the last contender on Mount Fujikasane, defeated, Haku had not only eradicated all the demons but also bested every competing swordsman, securing a Hashira seat with undeniable prowess.
Perhaps because his performance was so dazzling, when Haku descended the mountain to the torii gate, the previously arrogant swordsmen looked at him with newfound respect.
As for the lower-ranking Demon Slayer Corps members, their gazes were filled with outright admiration.
Undoubtedly, in the Demon Slayer Corps, which fought demons on the front lines, strength reigned supreme. Weak swordsmen didn't survive long.
And in their current dire straits, the Corps desperately needed strong leaders.
Given Haku's unassailable performance, the temporary council of trainers and swordsmiths unanimously approved him as the new Water Hashira.
The defeated swordsmen competed for the remaining eight seats based on their demon-slaying tallies.
After comparisons, the other eight Hashira were chosen: Nezuko as the Sun Hashira, Inosuke as the Beast Hashira, Zenitsu as the Thunder Hashira, Kanao as the Flower Hashira, Genya Shinazugawa, and four others.
With the nine Hashira confirmed, the Demon Slayer Corps promptly convened the Hashira Meeting.
Since Haku had decisively defeated all other Hashira during the selection, the meeting naturally centered around him.
Soon, the Corps presented Haku with reports on recent demon activities and the challenges they faced.
As he reviewed the documents, Haku's expression grew grave.
According to the Corps' intelligence, after the previous nine Hashira's betrayal and the inexplicable disappearance of the Twelve Kizuki, demon activity had quieted for a time.
But in the past one or two months, demons had become increasingly active.
From remote forests to populous cities, demon attacks on humans had surged. If these incidents were marked on a map, it would reveal that demons had gone rampant, as if out of control.
Zenitsu spoke up, "If this trend continues, it won't be long before demons are no longer a secret!"
Genya Shinazugawa added, "I think we should first hunt down the Corps' traitors!"
Zenitsu glanced at him. "You mean…?"
Genya said coldly, "The betrayer Hashira, of course. If we don't find and eliminate them, what right do we have to bear the title of Hashira?"
Haku shot Genya a glance.
Though he didn't understand why Genya was so fixated on the traitor Hashira, he knew they were already dead—killed in the distant shinobi world!
Kanao said, "We're Demon Slayers first, Hashira second. Our primary duty is to hunt demons!"
Haku nodded. "Kanao's right. No matter what, we must first suppress the demons!"
He picked up a document marked as top secret. "What's this about?"
A lower-ranking swordsman stepped forward, saluted Haku, and explained, "Water Hashira, sir! This document was recently compiled. It details four locations that have gone completely silent!"
Inosuke asked, "What do you mean, 'gone silent'?"
The lower-ranking swordsman said helplessly, "Whether it's the swordsmen we sent or civilian travelers, none have returned from those four places. It's as if…"
Zenitsu exclaimed, "How is that possible? These places… and this one—I remember they're major cities! How could they lose all contact with the outside world? Even demons couldn't devour entire cities overnight!"
The swordsman shook his head. "I'm sorry, we don't yet know what's happened in those places."
"Even cities have fallen…" Haku murmured, his mind racing with possibilities.