Yushiro closed his eyes, concentrating on looking through the Infinity Mansion to find every last demon slayer. He'd managed to get the demon to open enough doors for all the lower-level slayers to get out. Now he only had a couple of people left, either still fighting demons or—
Wait… was that…? There was something off about the demon he'd just seen. It wasn't the first one he'd come across that seemed strange (they were demons after all), but something about this one…
Then something changed… something with Nakime. Before he could stop her, she moved and her fingers plucked the biwa strings
Twang.
Yushiro almost panicked. That must have been a command from Muzan, but Yushiro hadn't heard it – not directly. Not even tangentially.
And then, he watched the very demon he'd been studying as they, and their meal, fell through a shoji door. Almost frantically, Yushiro went looking for them again, finding them in a room near Muzan, scrambling for their meal again.
Yushiro frowned. Why? Why would Muzan want the demon there?
Just as he thought that, he turned his attention to Kamado, who had just gotten to the shaft where Muzan had holed up.
Get him, he urged Kamado.
Yushiro could no longer sense anything but the barest hint of Tamayo-sama's presence, and he wanted that monster to pay.
Get him, Kamado!
The red-haired demon shot up the shaft, claws extended and ready to slash, but then the mass of flesh burst apart and Muzan – that had to be Muzan – shot down, aiming a punch right for Kamado. Yushiro wanted to cry out, but could only watch as the two demons met in mid-air, seemingly in a stalemate.
This… this was not good.
They had to get Muzan to the surface… which meant they had to kill the Biwa Demon, which meant he had to stop watching that fight and do what he'd said he'd do – get everyone out.
You'd better win, Kamado, he thought to himself as he gritted his teeth and kept looking through the mansion for people to save.
xXx
Nothing felt real to Sanemi. Months ago, he'd been the Wind Pillar, a human with a chip on his shoulders ready to take on the darkest side to the world or die trying. Then he'd been turned into a demon, had to deal with everything that came with that, and just when he'd started to get a little better, Muzan himself had attacked – Muzan and all of his Kizuki. They'd killed Oyakata-sama (he winced at that thought – it hurt), but at least he and the slayers had just killed Waxing One in return. It wasn't enough, though. And everything had happened so fast…
Perhaps he'd never thought the Demon Slayers could truly win? Was that it? Had he been fighting for what he saw as a lost cause from the get go? Or was it just that he'd never thought he'd survive it?
Probably that.
(Did being turned into a demon to save his life count?)
That had been a big part of why he didn't want Genya in the Corps. It was a death sentence. Every Hashira knew it, and the non-delusional slayers knew it…
He wanted Genya to live so badly…
He wanted one of them to live.
Something caught on the edge of his hearing, drawing him out of his thoughts and he paused, holding up his hand so the two Hashira behind him would know to stop.
"What is it, Shinazugawa-san?" Rengoku asked, way too loudly. And happily. Especially for someone who obviously had a broken nose. It made Sanemi want to shake some sense into him, but he took a deep breath and pushed that thought aside. He could… talk to the other man about his demeanor later.
"I think I hear a demon," he said.
Rengoku blinked at him. Himejima said nothing, just staring with tears still dripping down his cheeks.
Sanemi rolled his eyes. "Another demon. Low level… eating."
Himejima automatically whipped out his prayer beads and began to say mantras. Rengoku's smile dimmed ever so slightly, but he nodded emphatically. "Then let us go and do our job!"
"Our job is to find Muzan," Sanemi pointed out, but it was half-hearted at best. He had no issues taking out a low-level, and it probably wouldn't take them too far out of their way… especially considering they didn't know which way Muzan was. "One of us should go take him out and meet back up."
"I don't believe we should split up! Even if Yushiro-san has taken care of the Biwa Demon, finding each other again could be difficult! And we will all likely be needed to fight Muzan!"
Well, there went his plan to go off on his own, because Rengoku may be way too loud and way too bright and way too boisterous, but he also wasn't wrong. Unfortunately.
Himejima just continued with his mantras. Of course.
"Fine," Sanemi said tiredly. "This way."
He led them down the hallways, pausing at intersections to see which way would be best. After only one or two halls, he heard something else…
Whimpering.
The human!
"Whoever it's eating is still alive!" Sanemi hissed and took off down the halls at a dead run. The other two followed on his heels.
It took them too long to get there – he wanted to get there now.
Sanemi grit his teeth and took his sword out. He turned the final corner to see a demon, their back to him and… wait… that was a slayer's uniform!
What the…
And it was eating… another demon?
Sanemi's eyes widened as he realized what was going on. He'd already charged, was about to take off the demon's head, but changed trajectory at the last moment, causing his blade to miss the neck and head by millimeters. The eating demon panicked and ducked (way too late, kid), scrambling back from him, blood dripping down his mouth and staining the front of his uniform. He also had very small hands… weird.
He stared up at Sanemi, eyes wide in fear, but then bared his teeth. Sanemi rolled his eyes, then bared his own back. The kid whimpered and backed off. Good. That meant they didn't have a fight on their hands. Or at least it lessened the chance.
"Shinazugawa-san," Rengoku said happily, "why did you miss?"
The wind pillar sighed. "He's eating a demon. He's one of Kamado's."
"Kill… me…" the demon – the one the first one had been eating – said. Sanemi glanced down at him and saw he'd been pinned in place with a sword… a nichirin sword. To the neck. If the demon moved much, he'd kill himself.
Sanemi hated how his mouth watered at the sight.
"Oi, you like being a demon?" he decided to ask, kneeling down.
The guy on the floor, with pale skin and blue hair spread around him, looked up at Sanemi like he was crazy. Oh, he also seemed to be slowly growing back his missing arm. Probably the one the other demon had eaten…
Really best not to think about it right now. (Or how tasty the other arm was starting to look…)
"How am… I supposed… to answer… that?"
Sanemi shrugged. "Fine. Do you like being one of Muzan's demons?"
If anything the look of incredulity increased. "You said… his name…"
The Pillar rolled his eyes. "Yeah, I did. Answer the question."
The demon frowned. "Is there… any other… choice?"
Eh, good enough for Sanemi. "Yeah, there is."
"Serious… ly?"
The Wind Hashira nodded. "If I told you the other guy was better?"
The demon continued to breathe harshly as he thought. "Can't be… worse."
Sanemi snorted. "You ain't wrong. Better than dying?"
More silence, except for the slayer demon's soft growls in the background. Sanemi hadn't forgotten him and wouldn't let him attack anyone, but the kid seemed to understand he wasn't the strongest one there. Good.
"Yes." The demon on the ground said.
"You willing to go through a little pain to get away from him?"
The demon just seemed resigned at this point. "Yeah."
"Ok, then. Gonna give ya some blood." Sanemi scratched his finger and willed it to not close, trying to force blood into the cut. It worked. A little too well.
"Shinazugawa-san! What are you doing?" Rengoku asked.
Trying to see if he could save someone. (He tried not to think of Tokito's lifeless body… and failed.) "An experiment."
"Sword…" the demon on the ground said, before his mouth filled. Right, he couldn't swallow with that there. So the white-haired demon reached for the nichirin blade.
The slayer demon growled a little louder and Sanemi turned his own growl on the kid again. He slunk back, but didn't look happy about that. Whatever.
He pulled the sword out and the demon swallowed. He sat up for a moment and looked around, frowning up at Sanemi. "I don't feel any—urk!"
The demon bent over suddenly, clutching his stomach, and then screamed. After thirty or so seconds, he passed out. Sanemi blinked down at him, then looked back at Rengoku and Himejima. The Flame Pillar raised an eyebrow (still smiling though… seriously, why?) and Sanemi sighed.
"What happened?" Himejima asked calmly.
"We have come across two demons! One of them, as you know, is Kamado's and the other is not… and Shinazugawa-san decided to see if his blood could turn someone into one of Kamado's demons!"
Himejima frowned and opened his mouth to speak again, but the slayer demon squeaked. Like… in fear.
That… what?
Sanemi turned to the kid, who was staring at Himejima, face pale. His body tensed and Sanemi had to rush forward to catch the brat before he ran away. He lifted the kid in the air, his legs kicking and flailing as he growled and shrieked.
"Oi," the Wind Hashira shouted, "You're scared of them but not me?"
"That poor child," Himejima said, tear-flow somehow increasing. Shouldn't he dry out or something? How did he (the literal Stone – not Water – Pillar), have that much water in his body?
"I think I know him," Rengoku said boisterously. "He looks familiar… I think he's the Lightning Tsuguko!"
To their surprise, Himejima froze, not even speaking.
When he did finally talk again, he just said one word… or name.
"Kaigaku?"
xXx
Tanjiro saw Muzan – his smug smile, his new look with white hair, mouths all over his body, his slitted eyes. The time-traveler remembered how much he utterly despised this being who thought he was so superior. This was the farthest Tanjiro had gotten since his first life, and he would not let this monster win again!
He. Would. Not.
But he needed to keep a calm head. So he just smiled and tipped his head to one side. "Nice to meet you!"
Muzan laughed…
And the fight began.
Attack after attack came at Tanjiro. Muzan's arms grew and shot at him, a wall of muscle, sinew and bone (among other things, he swore he saw tentacles and spikes in there) destroying walls and hitting like freight trains. Tanjiro willed his hands larger and redirected the attacks he couldn't dodge. Then he hit the wall, feet first, and jumped away down the shaft, bouncing off the sides and avoiding the strikes destroying where he'd just been… again and again and again.
The bottom of said shaft came into view and he narrowed his eyes. Well, fine. He dodged one final time, hit the bottom and redirected his energy, shooting up and drawing his sword in one smooth motion.
"Hinokami Kagura: Burning Bones: Summer Sun," he whispered, whipping his sword around to defend and redirect again. The giant appendages hit the walls, crushing them, but it created an opening. Muzan's eyes grew wide. "Sunflower Thrust!"
Tanjiro's sword went right through the other progenitor's neck, but instead of looking worried, he just grinned.
Limbs sprouted from Muzan's back, curling around in the blink of an eye, closing in, and Tanjiro saw he'd been lured into a trap. Well, fine.
He, too, grinned and bit his lip. Hard.
"Demon Blood Art: Demon Fire Explosion." His fire burst out from him and burned. Muzan screeched, but Tanjiro pushed the fire to destroy everything of the 'Demon King' himself in the vicinity, down to his very spirit. If Muzan could mark him, what would stop him from doing the same? What would—
Pain suddenly lanced through his eyes and he gasped, his fire going out. He blinked as his vision returned. What… what had that been?
"So, you've grown more powerful," Muzan said from above Tanjiro, on a ledge about three floors up. The red-head landed on the edge of a hallway himself, pushing what had happened in his eyes to the side for now as he looked up. He'd figure that out later. He had to concentrate on the fight. Here and now, he told himself.
The old Tanjiro would have likely attacked Muzan again, angry and focused. This Tanjiro knew he had to wait for the right moment, so he took a deep breath and allowed his anger to fall to a simmer – the controlled, orange glow of coals instead of the raging inferno.
Then he shrugged and smiled. "Yup."
"It won't be enough."
Tanjiro felt his smile strain a little. What did Muzan expect him to do? Turn around and leave? Just give up? Probably.
Good thing that in this life, he didn't know Tanjiro at all.
"To kill you, I'll make it enough*."
Then Tanjiro did what he usually did: He let his actions speak for him, using both his breath style and his demon strength to attack, shooting up the shaft in a blink. To his frustration, the monster retreated. Gritting his teeth, Tanjiro followed down the hallway and stopped when he entered a large room. Muzan stood at the other end, grinning maniacally – confidently, in front of a shoji door. Something… was off. The time-traveler could smell blood – human blood. It came from a dead body, but another demon was feasting behind Muzan.
Tanjiro's instincts screamed at him to stop and take in the situation. He had to proceed with caution. This was another trap, but while he'd easily outmaneuvered the last one, he of all people knew how Muzan's traps could hurt. If the time-traveler wasn't careful, he could lose this fight.
(Or himself… as much as he wanted to tear this man apart, he was having a hard time holding back his demonic instincts.)
"As expected, you have no fear. Such is the prerogative of the strong," Muzan said. Then his smile widened. "But you are centuries too early to pose a true challenge to me."
Tanjiro snorted. "Like Yoriichi was?"
The older progenitor's eyes narrowed and his smile fell into an ugly scowl. "You are no Yoriichi."
Fair. Tanjiro could give him that. So he shrugged. "No. But I don't have to be to beat you."
The demon king's smile returned, far angrier and more vindictive than before. "You don't understand. You've already lost." With that, Muzan stepped to the side, opening a half-closed shoji door as he did. A demon knelt in front of a dead body, eating. Tanjiro could see the feathers on said demon's head, black, dark blue, and… red? And yet, it reminded him of a crow.
Then he recognized the haori the demon wore. Blue… with white clouds…
Urokodaki-sensei's haori, the one he'd lent to Tanjiro and Nezuko for their Final Selections…
And the one he'd probably lent to…
"Takeo…" Tanjiro breathed. He felt as if everything inside his body had been plunged into ice. Why? Why was he here? He shouldn't be here! Giyuu said he was at the edge of Urokodaki's training area! He was supposed to be safe! Why wasn't he safe?!
"I like that look on your face."
Tanjiro was back on the mountain, looking in at his family, lying in a bloody mess. All dead. All dead. DeaddeaddeaddeaddeaddeaddeaddeadDEADDEADDEADDEAD...
"Boy, come here."
Don't… Dontturnaround, Tanjiro silently begged, hating how his legs wouldn't – couldn't – move. He couldn't feel air in his lungs… he couldn't breathe…
The boy turned around. The feathers over his face were smaller, shorter, but there, especially across his nose and forehead, making it look very beak-like.
But it was undoubtedly Takeo.
He had blood dripping from his mouth, obvious fangs visible, and held flesh in one, clawed hand. Without so much as any recognition, he glanced at Tanjiro, then scurried over to Muzan, who put a hand on his head, ruffling his hair, almost affectionately. Almost.
Don't touch him! Tanjiro wanted to scream, but words wouldn't form. DonttouchhimdonttouchhimDONTTOUCHHIM!
"This one will conquer the sun for me. Thank you so much for allowing me to find him." Muzan looked up and his grin widened. "After all, if you hadn't escaped me that first time, I may have accidentally killed him."
Tanjiro's chest squeezed painfully. Why? Too tight… too tight!
"You know, I think he's already gotten stronger. Must be a family trait. He's certainly ready for more blood now."
And Muzan stabbed Takeo's neck with his finger. Takeo gasped, eyes rolling back in his head.
The coals of Tanjiro's anger burst into flame, growing larger and larger, until they were no longer flames but raw plasma.
He had to save Takeo…
A sun in his very soul.
But he couldn't.
His brother was a demon.
Tanjiro had failed.
Again.
Something inside of him snapped at that realization and burned away as if it had never been.
He had to make Muzan pay.
And he would.
His vision faded into red. Something smelled so good… and for once, he embraced the hunger. His mouth watered… A grin slid onto his lips. He licked them, gaze focused on the meal in front of him – on the lesser beings.
Finally, he could satiate that desire that he'd never allowed himself to give into before.
"Demon Blood Art: Demon Fire Explosion."
And the world burst into flames.
xXx
AN: FANART on my AO3! This one's seriously creepy, guys. You've been warned.
*Pin and SmolAvidReader – as well as many other people on my discord – helped me come up with these lines. Thank you for that! Also, thank you to Found and Quathis for your help beta reading!
Discord: discord. gg/xDDz3gqWfy (no spaces)
