Within the Demon Slayer Corps, the official requirement to ascend to the rank of Hashira was to slay fifty demons or to defeat a member of the Twelve Kizuki.
Yet the power of the current nine Hashira far surpassed this minimum condition. Each one of them was extraordinary, a warrior who had long since gone beyond such simple standards.
Just as the Twelve Kizuki differed widely in strength from one another, so too did the Hashira vary in power.
A swordsman who had only just become a Hashira might not initially stand among the most formidable, but through years of training, battle, and the tempering of their will, each grew into true paragons.
The present generation of Hashira was one of the most formidable lineages the Corps had ever seen.
Among them, the strength of Rengoku Kyojuro stood tall even within that elite circle.
He was undeniably powerful, a warrior who had touched the threshold of the highest realm. His aura radiated like a flame that could ignite the very air around him.
Even Akaza, the Upper Rank Three of the Twelve Kizuki, would later clash with Rengoku and be unable to hide his admiration. A
gain and again, Akaza would attempt to persuade Rengoku to abandon his humanity and embrace immortality as a demon.
Li Xuan's instincts, keen and unerring, already warned him of the sheer force standing before him now.
He could sense that this Flame Hashira was a mountain of power. Without using his demonized abilities, Li Xuan doubted he could triumph over this man.
"The Flame Hashira," Li Xuan murmured under his breath.
"You know me?" Rengoku asked, his sharp hearing catching the quiet words.
Li Xuan inclined his head. "My master spoke of you once."
In truth, Urokodaki Sakonji had never said any such thing. Li Xuan fabricated the excuse with ease, his expression betraying nothing.
"Then it is good that the two of you may grow acquainted," said Kagaya Ubuyashiki gently, his wife supporting him as he spoke. His warm smile carried the serene calm of one who guided many lives.
"Understood, Master. Please return and rest at once," Rengoku urged with concern.
The Ubuyashiki family had borne a dreadful curse since the birth of Muzan Kibutsuji. Each heir inherited not only foresight but also a fragile body wracked with illness and a shortened lifespan. For them, strength always came at the price of suffering.
"Very well," Kagaya replied softly, turning back toward the house with his wife's assistance.
Once the Master had gone inside, Rengoku's blazing eyes focused upon Li Xuan. "Tell me your name," he asked, his voice filled with vitality.
"Li Xuan," came the reply.
"Li Xuan…" Rengoku repeated, his spirited face breaking into a bright smile. "The aura you released just now, I felt it clearly. You are very strong. Would you like to spar with me?"
Li Xuan's expression remained calm. "I must decline, Rengoku. I have no interest in battles where I cannot be assured of overwhelming victory. I prefer not to risk uncertain duels. With the system I possess, I need only bide my time to surpass others. There is no need to spar when I can steadily grow beyond them."
Yet even as he thought this, a subtle idea took form. A faint smile tugged at his lips, breaking through his usual composure. He extended his hand toward Rengoku in a gesture of friendship.
Though Rengoku was momentarily disappointed by the rejection of his challenge, his nature remained generous and open-hearted. With warmth in his eyes, he clasped Li Xuan's hand firmly, offering nothing but genuine goodwill.
"Then I shall look forward to the future, Li Xuan. If you ever have questions, come to me. I will help however I can."
Li Xuan's smile deepened slightly. "Of course."
[Sign-in successful]
[Flame Breathing: Mastery. One of the five foundational Breathing Styles derived from Sun Breathing. Through its practice, Demon Slayers gain tremendous strength, allowing them to fight demons on equal footing.]
Though Li Xuan had not touched Kagaya and thus had not gained his foresight, acquiring mastery of Flame Breathing from the Flame Hashira was still a worthy prize.
[Notice: Water Breathing can be fused with Flame Breathing.]
Then fuse them, Li Xuan thought silently.
[Notice: Fusion requires both Breathing Styles to be at the same rank. Water Breathing: Expert. Flame Breathing: Mastery. Fusion not possible.]
His brows lifted faintly. So the levels must match…
Li Xuan's Water Breathing had long surpassed mastery, having reached the rank of Expert. Yet his luck today had not given him Flame Breathing at the same level. He had only acquired mastery, and the fusion could not occur.
That meant only one path remained.
Li Xuan turned his gaze back toward Rengoku's face. After a pause, he said, "I have changed my mind. Would you allow me to stay with you, Rengoku, and train alongside you each day? We could improve together."
"Of course," Rengoku replied without a second thought, nodding eagerly.
Though he did not know why Li Xuan had altered his decision so suddenly, the thought of sparring daily with someone of comparable strength filled him with excitement.
For now, Rengoku's duty was to remain near the Master, standing as a blazing shield should demons attempt to strike the heart of the Corps.
It was not a mission heavy with travel, yet it left him with long hours of stillness. To have a sparring partner by his side was a welcome change to relieve the monotony.
"Shall we spar now?" Rengoku asked, his voice alight with enthusiasm.
Li Xuan gave a polite smile. "Perhaps tomorrow. I am tired today."
"Very well then," Rengoku replied with good-natured cheer. "Come, Li Xuan. I will show you to your room."
He led Li Xuan to his residence, a house filled with warmth and the subtle scent of charred cedarwood. He arranged an empty room for him, then instructed the Corps attendants to provide whatever assistance Li Xuan required.
…
The next day, the sound of steel rang out across the courtyard.
"Cheng!"
Two Nichirin blades clashed violently, their collision creating a resonant shock that reverberated through the air. One blade shone with a fierce crimson glow, the other radiated with a deep, shadowed blue.
The force of their strikes tore through the courtyard, sending gales of wind outward in every direction. The trees shuddered, petals and leaves scattering like sparks upon the wind.
Both swordsmen leapt back simultaneously, lowering their blades.
"You have improved astonishingly fast, Li Xuan!" Rengoku declared, holding his flame-colored sword marked with the words "Destroyer of Demons." His arms tingled with numbness from the sheer force of the clash, and admiration lit his eyes.
Li Xuan gave a soft laugh. "You flatter me, Rengoku."
He wore the Corps uniform, altered to fit more loosely, his tall frame moving with calm poise. In his hand, the dark blue Nichirin blade gleamed with an eerie brilliance, its glow harmonizing with the sharp beauty of his features.
"When you first sparred with me, your strikes lacked power. Yet now you have clearly surpassed me in raw strength," Rengoku admitted, shaking out his arm to ease the lingering ache.
"That is only because you have not used your Breathing techniques," Li Xuan replied evenly.
"You have not either," Rengoku countered with a fiery grin. "And yet, even without Breathing, your strength has soared beyond mine in just one month. Such progress is truly astonishing."
As he spoke, Rengoku's thoughts flickered to another prodigy, the Mist Hashira Muichiro, who had reached Hashira rank within mere months.
But unlike Muichiro, whose progress eventually plateaued, Li Xuan's growth showed no signs of slowing. His power surged like a river in flood, rushing forward without end. It was almost terrifying.
"You praise me too highly," Li Xuan said, sliding his blade back into its sheath. He stepped forward and, as had become his habit, extended his hand.
Rengoku clasped it warmly, his smile broad and unshaken. For him, this handshake was a simple gesture of camaraderie after each spar, a ritual that marked their bond.
To Li Xuan, however, it was something more.
[Sign-in successful]
[Acquired Flame Breathing: Mastery. Duplicate. Can be stacked.]
Stack the skill.
[Flame Breathing upgraded: Expert]
[Expert-level Flame Breathing can now fuse with Expert-level Water Breathing. Proceed with fusion?]
Yes.
[Fusion successful. New Breathing Style created. Would you like to name it?]