Demon Slayer AU

By: FunahoMisaki

(A/N: I own nothing and it was just a little blurb that hit me so I had to write it. Maybe a bit OOC.)

"Tanjiro-kun!" The pillars were more than happy to see Tanjiro again, after all he had given each of them closure with their families and some last messages that they had needed to hear.

"Hi everyone. It's nice to see you all again." Tanjiro was more than happy to hug anyone who came and gave him a hug.

"Here comes Oyakata-sama." Someone called out and everyone kneeled to the man, Himejima being the one to thank him for his presence there.

"Hello again everyone, Tanjiro-kun it is nice to see you again too." Kagaya said smiling softly at all of them as he sat with his son by his side.

"It is nice to see you as well Oyakata-sama." Tanjiro said respectfully as he smiled brightly at Kagaya.

"Now then I'm sure you all are at least somewhat aware of why this meeting was called." Kagaya said and making the Hashira nod or give other noises of affirmation.

"Sir I have something to report about what happened on the mountain." Giyu said respectfully and he glanced at Tanjiro who nodded steadily.

"What is it Giyu-kun?" Kagaya asked smiling indulgently.

"It seems Tanjiro-kun has developed a way for those who use breathing techniques to heal others." Giyu said and everyone paused for a moment at this.

"I don't think I heard you right Giyu-kun." Kagaya said with a small baffled smile while his son looked up at him confused.

"He said that Tanjiro-san developed a way for those who use breathing techniques to heal others father." Kiriya said making his father nod slowly and pat his head in thanks.

"It was quite something to witness. He used his technique to heal a girl who had two badly broken arms after being controlled by one of the spider demons." Shinobu added in and the others immediately looked at Tanjiro.

"Ah you shouldn't give me all the credit. I developed the technique while talking with Tamayo-obaa-sama who is a doctor." Tanjiro said trying to give his ancestor the praise she deserved for it.

"Lady Tamayo? You call her such a title?" Kagaya asked and the pillars heads whipped towards him. Lady Tamayo? He even addressed the woman in question so respectfully?

"Ah well I'm not sure if she noticed it or yet but she had a child when she was human who survived and ended up having children of her own. Eventually that childs family came all the way down the line to mine, she's my ancestor on my mothers side according to the spirits around her and us." Tanjiro said sheepishly as he rubbed the back of his neck.

"I see…certainly a demoness who's been alive since Yoriichi-sama's time and who broke from Muzan's control would have plenty of ideas about what the techniques could do." Kagaya said nodding his head in understanding.

"She's also a doctor now and makes medicines and poisons, so she knows a lot about healing and taught me a bit when I showed interest. That's how I was able to create the healing technique." Tanjio explained while the Hashira were slowly processing the fact that there was a demon that has been alive since Yoriichi's time and was free of Muzan's control roaming around somewhere.

"With your permission Oyakata-sama I'd like to try something with my healing technique." Tanjiro said and Kagaya tilted his head slightly.

"I'm quite interested in this technique. Feel free to do whatever it is you are considering." Kagaya said giving him permission since his instinct was yelling that it would be okay and a great idea.

"Thank you sir." Tanjiro bowed and then stood and approached Kagaya. Everyone watched as Tanjiro stopped right beside Kagaya and inhaled a breath so large that it felt as if he were Kirby.

Concentrating until his hands began to glow with a bright but warm light, Tanjiro put his hands near Kagaya's head and focused intently.

Giyu and Shinobu's eyes widened at what he was doing and they quickly shushed the other Pillars when they moved to question Tanjiro.

"This warmth…" Kagaya murmured amazed and he flexed his hand a little bit, feeling the warmth extend all the way towards his finger tips and toes.

"Oyakata-sama please don't move too much. It's an incredibly difficult technique it appears and it requires his entire focus and concentration." Shinobu said quietly and Kagaya became still and silent although his eyes were widening.

So were the eyes of the pillars as they saw the ugly purple marks going across his upper face and blinding him in his eyes slowly begin to recede. The purple marks slowly began to crawl back up his face towards his scalp and towards Tanjiros warmly glowing hands. And as they passed his eyes, the white of his no longer seeing iris's began to fade back into a lavender color that while still pale could now see.

Kagaya looked around with his eyes in wonder and there was a small but happy smile on his face as he glanced down at his son beside him and then at his other 'children' in front of him. Glancing up as much as he could without moving anything but his eyes, Kagaya saw the narrowed intensely focused gaze of Tanjiro on his head and the boys face was set in determination as Kagaya felt new strength enter him. He felt stronger than he ever had before.

Tanjiro released a heavy breath finally, heavy enough it nearly bowled young Kiriya over and he smiled at Kagaya.

"I'm almost done. One more time and the curse should be fully gone from your body. I'll need a really deep breath and there'll be a lot of oxygen in my blood so it's best if I cure you and your children all at once." Tanjiro said and Kagaya nodded mutely and looked at his son.

"Run now Kiriya. Fetch your sisters, and your mother as well." Kagaya said softly to his son who nodded and stood before running faster than he had ever done so before.

"You are an amazing godsend Tanjiro-kun. Never once did I think my curse would recede or could even be removed…" Kagaya said and he flexed his hand for a moment before standing and patting Tanjiro's head.

"Ah I'm just doing what I can to help." Tanjiro blushed and looked down and was it Kagaya's imagination or did the boy seem slightly unsteady on his feet.

"And you are doing amazing. If this kind of healing technique can be taught to others…" Kagaya trailed off as he bade the boy to sit and rest until his family got here.

"It wouldn't be the exact same. It'd be different for each style of course. For example Insect or Water style would probably work better for those who are poisoned, Flame style for those who are freezing, and who knows what kinds of injuries the other styles could heal. Especially if it was someone like a Hashira who is much better trained than me. Sun style is just better for curses and perhaps bones as well because of it's very nature." Tanjiro said shaking his head slightly and the Hashira were gaping in disbelief at him.

"Tanjiro-kun…I never thought I'd see the faces of my children again. Let me thank you for that at the least." Kagaya said softly and Tanjiro beamed at him.

"Don't thank me until I'm done healing all of your family sir." Tanjiro chirped as there were running feet.

"Dear! Kiriya just said that…that…" Amane trailed off as she stared at her husband wide eyed when he turned and looked her right in the eyes, their children right on her heals and racing towards their father.

"I'll excuse it this one time because it's such a big occasion but no more running indoors." Kagaya said smiling and embracing each of his children, kissing their heads as they all beamed up at him and held onto his haori or kimono.

"Dear…you…you can…" Amane was stunned as she moved forward towards him and sank to her knees beside him and their kids, the Hashira and Tanjiro all turning their heads away to give the family some privacy.

"I can see again…you look just as beautiful as I remember Amane." Kagaya said softly as he smiled at his wife who had tears in her eyes that freely fell as she hugged her husband and kissed him gently, which he gladly returned.

"I'd never complain or question such a miracle but…but how is it that…how…" Amane was breathless and overjoyed as she pulled out of the kiss and Kagaya glanced at the boy beside him pointedly.

"Tanjiro-kun here not just uses Water and Sun Breathing but with some help from an ancestor of his who is a doctor he managed to make a healing technique…The sun is quite good at healing curses…" Kagaya said and he trailed off when his wife turned and pulled Tanjiro into a hug, causing the boy to give a surprised squawk like noise that had the Hashira snickering.

"Thank you. Thank you so much. You have no idea how much this means to me…to all of us." Amane said and there were tears in her eyes as she hugged the boy. He had healed her husband so that he could see again, had bought them more time together.

"There's no need to thank me. I'd do the same for anyone who needed it…besides I still have to finish removing the curse entirely from Oyakata-sama and the young princesses and prince." Tanjiro said and Amane released him with a nod, bowing her head slightly in apology for her behavior.

Tanjiro looked over the assembled family with a critical eye and then nodded once.

"From what I can tell the curse is more heavily effected on the older princesses and the young prince. So after I heal Oyakata-sama I won't be able to move much while keeping concentration so you will have to approach me I'm afraid. We should go from eldest to youngest since the youngest princesses are almost untouched by the curse yet." Tanjiro said and the family nodded their heads.

"It's easier if I have my hands near where the curse is at, and the main focus of it is gathered around the tops of your heads. So pardon me for standing." Tanjiro said and he pushed himself back up to his feet, and the other Hashira were sure they had just noticed Giyu tensing a little bit as he watched Tanjiro like a hawk.

Once more Tanjiro inhaled a breath as big as Kirby and held it, his hands glowing again after a mere moment as he placed them near Kagaya's head. After several more moments of quite Tanjiro nodded ever so slightly and moved his hands just a bit away from Kagaya, which caused the oldest twins to approach. He started with Nichika and then after two or three minutes he moved his hands a little towards the other twin who approached him.

He repeated this process for Hinaki for just as long before he moved the tiniest bit and Kiriya approached, Tanjiro kneeling down now and the other Hashira were sure that Giyu was tensed up and prepared to move forward at any sign and they were confused as to why. Kagaya frowned slightly as well…one of his instincts was yelling at him to stop Tanjiro but…but his other instinct was telling him to let Tanjiro keep going. To let Tanjiro finish removing the curse and heal his bloodline.

It took longer for Kiriya than it did for his elder sisters but when Tanjiro smiled slightly and moved his hands the tiniest bit, and the more observant people realized that his hands were starting to shake, the youngest twins approached. Compared to their siblings and father it took next to no time at all for Tanjiro to be finished healing Kanata and Kuina.

Finally he smiled as the glow faded from his hands and he moved them away from the youngest members of the family, letting his hands dropped back to his sides.

"Thank you Tanjiro-kun. You have no idea how much it means to all of us. To know that the curse will no longer affect our children…" Kagaya trailed off with tears in his eyes as he held his wife and five children. Tanjiro smiled weakly towards them and then, to their confusion, he turned his head towards the side of the yard.

When he let out the breath he was still holding, the other Hashira jumped back alarmed at the sight of blood falling from his mouth.

Giyu lunged forward and grabbed Tanjiro by his shoulders to keep him from falling from the low rise face first into the ground as the boy continued to cough and hack up blood.

"Tanjiro! Tanjiro listen to me! Slow deep breaths! Calm your breathing and try to picture the ruptured areas, slowly force them closed!" Giyu was near shouting orders to Tanjiro who gave a weak moan like sound before he coughed up another wad of blood.

"Kochou get over here!" Giyu yelled and Shinobu lunged forward as well, her hand immediately going for her stash of medicine and first aid supplies while Amane moved to help as well.

"His hands…" Amane was the one to notice the boys hands and her face drained of what little color it had in it as she saw how burnt the boys hands were and how they were discolored and looked a bit mangled.

"Tanjiro! Tanjiro stay conscious." Shinobu was ordering him to remain awake as she injected a blood clotting agent into his body to try and keep him from losing anymore blood.

"I'm…I'm glad…you'll…be okay…now…" Tanjiro rasped out as he turned his head slightly towards the wide eyed Kagaya and his horrified children, giving them a sunny but bloody smile.

"Tanjiro stay with us! Tanjiro!" Giyu was shouting now as he shook Tanjiro's shoulders a little bit and there was a rattle and a bang from Nezuko's box but no one was paying it any attention at the moment.

"We need to get him to Butterfly Estate now! Tanjiro stay awake damn it!" Shinobu's smile was gone as she looked at his hands and assessed the damage with a wince, and then forced up one sleeve to show that similar burn and ugly discoloration marks were on his arm.

"Don't tell me…" Shinobu's eyes were wide in horror and she cursed vividly again as she dug around in her pocket for another blood clotting.

"This should buy us time but I need my lab and medical supplies." Shinobu said and Giyu nodded once as he moved to lift Tanjiro.

Everyone was surprised when a very much not burning Nezuko grabbed her brother and gently carried him, her bamboo gag gone and her eyes narrowed.

"Where? Butterfly. Where?" Nezuko asked and Shinobu would be freaking out and investigating that later but for now.

"To the east! Towards the east with a large Cherry Blossom tree in the yard!" Shinobu barked out knowing that the demon would be faster than she would be. In a blur of movement Nezuko was gone and both Giyu and Shinobu were rushing off behind her.

"He just…He injured himself gravely to heal us…" Hinaki whispered with her eyes locked on the puddle of blood on the ground, her sister making a noise of agreement as she stared at the bloody marks left on the wood.

"Dear I have medical experience. With your permission I'd like to-" Amane turned to her husband who nodded once.

"Go. The children and I will be along shortly." Amane was immediately gone, running from the Estate to get to the Butterfly Estate and help with whatever she could.

"The meeting is ended for now. Everyone's dismissed." Kagaya said to the remaining horrified looking Hashira who all nodded slowly, each one taking off in the same direction.

"Come on children. Let's go make sure he's going to be okay yes?" Kagaya asked standing and each of his children immediately nodded, Kagaya scooping his two youngest into one arm while holding hands with his eldest with his free hand. Hinaki was also holding Kiriya's hand and Nichika was holding her little brothers older hand so that he was in between his two older sisters.

"He's going to be alright, right father?" Kuina asked worried and making Kagaya give her a small smile.

"Shinobu-chan and Amane are both helping him. I'm sure he'll be just fine." Kagaya said reassuringly as he walked his children towards the medical estate.

He hoped and prayed that the boy would be okay.