The sun was now fully in the sky, bathing the forest in soft light as the group made their way through the trees. The morning was calm, with the sounds of nature returning to normal after the events of the previous night. But despite the serenity, tension hung in the air as they moved deeper into the woods.
Tanjiro led the group, his senses keenly attuned to the forest around them. Nezuko walked quietly beside him, her gaze watchful as ever. Killua and Gon trailed behind, whispering to each other, while occasionally stealing glances at their new companions. Although there was trust growing between them, neither Gon nor Killua could shake the feeling that they were still outsiders in this strange new world.
"We should be there soon," Tanjiro said, glancing over his shoulder. "The Demon Slayer Corps headquarters is hidden deep in the mountains. It's not far, but we should stay alert. Demons are more active at night, but they can still attack during the day if they're strong enough."
"Sounds like our kind of place," Killua remarked, his voice dripping with sarcasm. "Hidden, remote, and surrounded by dangerous monsters. What could go wrong?"
Gon, however, didn't share his friend's skepticism. His usual excitement bubbled just beneath the surface. "I can't wait to meet the other demon slayers!" he said, eyes gleaming with enthusiasm. "Do you think they'll teach us how to use their swords?"
Tanjiro smiled softly at Gon's eagerness. "They might. But it takes years of training to become proficient in swordsmanship, especially with a Nichirin Blade. And using Breathing Techniques requires discipline and focus."
Gon's determination didn't waver. "That's fine! I'll learn quickly. Killua's already super fast, and I've been working on controlling my nen. If we can learn your techniques too, we'll be even stronger!"
Killua rolled his eyes but didn't argue. Despite his usual complaints, he knew Gon well enough to understand that once his friend set his mind on something, there was no stopping him. And truth be told, Killua was curious about these "Breathing Techniques" as well. If they were going to survive in this world, learning new ways to fight wouldn't be a bad idea.
As the group walked, Tanjiro's expression grew more thoughtful. "You mentioned something earlier, about nen. What exactly is it?"
Gon and Killua exchanged a glance. They had explained the basics of nen to people before, but the concept was always difficult for those outside of their world to grasp.
"It's hard to explain," Gon began. "Nen is a way of using the energy inside your body—your life force. Everyone has it, but only some people can learn to use it in different ways."
Killua nodded, adding, "There are different categories of nen users. Enhancers, like Gon, can strengthen their bodies or their attacks. I'm a Transmuter, so I can change my aura into other things—like electricity."
Tanjiro's eyes widened slightly. "That explains how you were able to move so fast last night," he said, looking at Killua. "I've never seen anything like it. In our world, we focus on breathing techniques to strengthen our bodies and enhance our senses, but what you're describing is on another level."
Gon grinned, clearly proud of their abilities. "Nen's really useful! But I think your breathing techniques sound amazing too. If we can combine what we know with what you know, we'll be even stronger!"
Tanjiro nodded thoughtfully. "That could be possible. I've never tried combining different fighting techniques before, but with everything happening lately, it might be exactly what we need."
Killua, always skeptical, raised an eyebrow. "What do you mean, 'everything happening'? You've said the demons are getting stronger, but why? Is it something to do with this Muzan guy?"
Tanjiro's face darkened at the mention of Muzan's name. "Yes," he said quietly. "Muzan Kibutsuji is the source of all demons. His power is beyond anything we've faced. And lately, there's been a shift… something's changing. The demons we've encountered are becoming more powerful, more unpredictable. I don't know what it means yet, but I fear that Muzan is planning something—something that could threaten not just this world, but perhaps yours as well."
Killua's eyes narrowed. "If he's that strong, then why hasn't anyone taken him down yet? You said your Corps has been fighting him for generations."
Tanjiro sighed, his hand unconsciously gripping the hilt of his sword. "Muzan is nearly impossible to kill. He can regenerate faster than any demon, and his control over blood techniques is absolute. Even the strongest of us—our Hashira—have tried to defeat him, but every time we get close, he escapes. And now, with these new demons appearing… I don't know what we're facing anymore."
Gon's expression grew serious. "Then we'll help you," he said firmly. "If this Muzan is a threat to both our worlds, we'll fight him with you."
Killua glanced at Gon, surprised by the sudden declaration, but he didn't object. Despite his usual cynicism, he couldn't deny that the idea of taking down a being as powerful as Muzan was a challenge worth pursuing.
Before Tanjiro could respond, Nezuko, who had been walking silently beside her brother, suddenly stopped in her tracks. Her body tensed, and her eyes flickered with that same protective instinct they had seen before. Without a word, she placed herself in front of Tanjiro, her gaze scanning the surrounding forest.
"Nezuko?" Tanjiro asked, his voice quiet but alert. "What is it?"
The others immediately picked up on the shift in atmosphere. Killua's instincts flared as he felt the change in the air—something was wrong. Gon's eyes sharpened, his senses kicking into overdrive.
Tanjiro's hand flew to the hilt of his sword. "Stay close," he whispered, his breath steadying. "There's something out there."
For a moment, nothing happened. The forest was still, the soft rustling of leaves the only sound around them. But then, from the shadows of the trees, a soft, almost melodic voice echoed through the air.
"I didn't expect to find the famous demon slayer and his sister here."
The voice was smooth, too smooth, like silk sliding over ice. It sent a chill down the spines of everyone in the group.
Killua's body tensed, his muscles coiling as his eyes darted toward the source of the voice. "Who's there?" he demanded, his hands already crackling with electricity.
A figure stepped out from the shadows, their movements fluid and graceful. It was a man, tall and pale, with sharp features and long, flowing hair. His eyes gleamed with a dangerous intensity, and the air around him seemed to ripple with dark energy. He wore an elegant black kimono, adorned with intricate patterns that seemed to shift as he moved.
Tanjiro's breath caught in his throat. He had seen this man before.
"No…" Tanjiro whispered, his heart pounding in his chest. "You're… one of the Upper Moons."
The man smiled, his lips curling into a grin that sent a shiver down their spines. "That's right. I am Nakime, one of the Twelve Kizuki. And it seems today's hunt will be more interesting than I thought."
Gon's fists clenched at his sides, his body trembling with a mixture of excitement and nerves. "One of the Upper Moons…?"
Killua's eyes narrowed, his body already preparing for a fight. "Looks like we found our next problem."
Tanjiro's grip on his sword tightened. This wasn't like the demons they had faced before. Nakime was on a completely different level. The air around them felt heavy, suffocating with his presence alone. And there was something else—a strange, pulsing energy that seemed to thrum through the ground beneath their feet.
Nen? Killua thought, his mind racing. No… something darker.
"Stay back!" Tanjiro ordered, his voice firm. "Nakime is dangerous—he's not like the others. We can't fight him carelessly."
Nakime's grin widened, his eyes flickering with amusement. "Oh? Are you afraid, demon slayer? I thought you'd be more eager to face me."
Tanjiro's jaw clenched, but he didn't rise to the bait. He knew better than to let his emotions control him in the presence of an Upper Moon. This fight would require strategy—and he wasn't about to let Nakime win so easily.
But before Tanjiro could move, Nakime's eyes shifted to Nezuko, and the air around them seemed to thicken with malicious intent.
"Ah, and there's the little demon sister," Nakime said, his voice soft but deadly. "I've heard so much about you. Perhaps today will be the day I bring your head to Muzan-sama."
Nezuko growled, stepping forward to shield Tanjiro, her claws already extended. But Gon and Killua weren't about to sit back either.
"You're not laying a finger on her," Gon declared, his voice hard and determined. His aura flared, the familiar glow of nen surrounding him.
Killua's smirk returned, his hands crackling with electricity as he prepared for battle. "We've dealt with worse than you. Let's see if you can keep up."
Nakime's eyes gleamed with anticipation, his body shifting as he prepared to attack. "Very well, then. Let's play."
The air grew thick with tension as the battle was about to begin.