Li Xuan stood by the river and murmured, "Where is Tanjiro..." He paused to recall Tanjiro's scent. His nostrils flared and his keen sense of smell sparked to life.
For a moment it felt as if the entire mountain poured its many life scents into his nose. Unfamiliar demon musk rushed past him. He picked up the faint human tang of strangers, the quick sharp smell of small animals, the delicate floral trace of Shinobu Kocho, the warm, fermented scent that was Nezuko, and then, faint but unmistakable, Tanjiro.
"Found you."
Something felt wrong. Li Xuan detected that Tanjiro's presence was weak, barely breathing. Even with his power boosted beyond the original plot, Tanjiro still seemed no match for Rui, Lower Rank Five.
Li Xuan's breathing deepened. "Full concentration." His form shimmered and dissolved, vanishing from the riverside.
...
"Water Breathing, Third Form, Flowing Dance." Tanjiro swung his Nichirin Blade. A spray of water followed his arc and he closed distance with nimble, careful footwork, each step measured and precise.
The demon before him had hair like silk and skin pale as milk. Its eye sockets glowed red, and its eyeballs were a strange mix of white and black. A line of crimson dots marked its cheek. It had the small frame of a child, yet within its gaze the words Lower Rank Five were etched like a curse. This was Rui, Lower Rank Five.
From Rui's hands sprang strands of pale silk that shot toward Tanjiro like a spider's web. Tanjiro dodged through them with practiced steps. Whenever he could not escape in time, he met a strand midstep with his blade and cut it. Compared with the original account where the threads were unyielding and the blade shattered instantly, this fight had already gone better. Tanjiro was finding openings and slicing many threads away.
Tsk. Rui curled his lip. His hands flushed a deep red as blood welled and flowed into the growing silk. The white threads turned crimson in an instant.
Tanjiro's blade struck the reddened strand and suddenly slipped through a gap. "My sword passed through... I cannot cut it. These threads are too tough."
In a heartbeat Tanjiro crouched and narrowly avoided a sweeping lattice. Even so, his Nichirin Blade snapped under strain. It broke cleanly with a metallic cry. "It broke," he gasped, shock and alarm cutting across his face. "What do I do now?"
He took a step back and placed himself between Rui and the wounded Nezuko. The Nichirin Blade was the demon slayers' lifeline. With it fractured, his fighting ability suffered greatly. Flowing Dance drained considerable stamina. Tanjiro had hoped to close quickly and deny Rui room to spin his web, but instead his blade fractured. His haori and uniform hung in tatters where the silk had grazed them, and his energy ebbed.
"Think." Tanjiro gripped the jagged hilt and spun thoughts feverishly, searching for a way out. "Think fast."
"Let your sister be mine." Rui suddenly extended an arm, his tone offering a ghastly bargain. "No." Tanjiro replied with fierce resolve. "Then die." Rui answered coldly.
Rui splayed his fingers. From them burst a tempest of red threads like a swarm of spiders. The countless lines wove together into an enormous net that descended to enclose Tanjiro and Nezuko. Once trapped, the net would slice them into tiny pieces.
"Blood Demon Art, Thread Prison." Panic rose in Tanjiro. When his blade had been whole it still could not sever those crimson lines. With only a broken sword he felt cornered by inevitability.
Memories flashed across his mind like an old lantern reel. His father appeared in the images. Snow fell as his father wore ceremonial robes and danced an offering to the fire god. "Our family works with fire," his mother had said. "To keep from harm and disaster, we offer a dance each year to the fire god." Fragments of talk with his father surfaced. "There is a way of breathing that does not tire, no matter how you move," his father had murmured while lying on the futon.
These recollections felt long buried but suddenly vivid. "Breathe, Tanjiro." The heavy voice of his father echoed in his memory. "Hinokami Kagura."
The rhythm of Water Breathing faltered and shifted. Tanjiro switched into the breathing his father had taught him. A new flame rose above the broken blade, softer and more luminous than the usual power of the Dance of the God of Fire.
"Round Dance." The fire blossomed and licked through the tightening red web, shredding the prison into ash. Tanjiro surged forward in that same instant.
He could not stop now. If he hesitated he risked suffering aftereffects from switching breathed techniques. He had to finish the kill without pause. His heart burned with a single prayer: cut down this demon.
"How?" Rui reeled at Tanjiro's sudden fury and retreated at high speed. While falling back he wove the threads into a braided snare and hurled it at Tanjiro. "Blood Demon Art, Killing Eye Cage."
The red strands proved brittle against the inferno. The instant they brushed Tanjiro's flame they blistered and burned away like webbing in a blaze. "Damn it." Rui's face twisted with panic. He prepared another move, but Tanjiro closed in with the blazing stub of his blade.
This would work. Tanjiro tightened his hold and drove the remaining length of the blade toward Rui's neck.
"Wait." A familiar voice cut through the moment. Li Xuan had appeared at Tanjiro's side and gripped his arm, stopping the strike. Even then Rui's head had already been torn from its body.
"Why?" Tanjiro blurted, but then he saw Rui's severed head tethered by a few lingering threads. He understood at once. Even a clean cut would not render Rui harmless if the head remained bound. Yet Li Xuan had come. He had saved the crucial moment.
Trusting Li Xuan, Tanjiro sagged down, drained by the breathing transition and unable to move.
"Well done." Li Xuan stepped forward, caught Tanjiro as he sank, and without fuss tossed both Inosuke and the weakened Tanjiro toward a now recovering Nezuko. Li Xuan had actually been nearby earlier but had held back. He knew this scene was vital for Tanjiro to awaken the full brilliance of the Dance of the God of Fire. He would not break that beat unless Tanjiro truly faced death. He had prepared to intervene only if necessary.
Why, then, did he block Tanjiro's final blow? Li Xuan admitted to a simpler motive. He was curious about Rui's Blood Demon Art. In the original tale Rui had sometimes detached his head as a tactic. Li Xuan could not guarantee the plot would play out precisely, and Rui had acted differently before the strike, binding his head with strands in a way that deviated from the script. Moreover Tanjiro's swing seemed genuinely lethal. Li Xuan feared the blow might destroy Rui outright, so he halted it.
"Who are you?" Rui's head twitched as threads drew it back toward its neck. "Why did you stop his blade?" The demon sensed the newcomer as human, and curiously he also detected a faint demonic aura at Li Xuan's waist.
"I am not proud of the reason," Li Xuan said, unsure how to explain. Was he supposed to confess he wanted Rui's Blood Demon Art?
"Then die." Rui's face contorted with rage and his fingers streamed more threads. In the next instant he found the man he aimed at gone.
"Behind you." Li Xuan tapped Rui on the shoulder. A faint prompt flickered in Li Xuan's mind.
[Check in]
[Check in successful]
[Acquired Rui, Lower Rank Five Blood Demon Art: Usable in demon transformation state. All of Rui's Blood Demon Art techniques are now obtainable.]
Li Xuan felt a spark of surprise at the message. The check in system typically granted Blood Demon Art abilities one by one. Sometimes it gave odd items. This time fortune smiled and he acquired the entire set in one strike.
Rui blinked at the voice behind him, confusion and doubt passing over his features. Li Xuan moved with lightning speed. Rui's fury cooled as if doused by cold water. "Since you have claimed it, you are no longer necessary," Li Xuan said. Rui spun to fire his threads, but a calm tone came from the side.
"Water Breathing, whatever the form is. One cut will finish things." Li Xuan drew his blade and spoke a phrase that humbled the demon. The sound of steel sliding from its sheath rang out, and Rui's consciousness dimmed as darkness closed around him.