Chapter 15 - Declaration of War

'Do I wish to die…? Maybe when I came to this world. I thought dying was the fastest way to get back home. After all, I trusted Dad…he wouldn't let me die. No matter what he says…as doting as he is. He wouldn't.'

'Does that mean somewhere deep inside, a part of me still wants to die? To go back home? And leave behind the friends I made, the people whose determination I have come to admire? And that hopeless girl…both of them. I can't leave them alone after all. I…wish to save this world…I wish them to have a happy life.'

She abruptly felt light appear in front of her eyes, realizing she was sitting up, gasping for breath, and her palms were on her neck, "Still alive…."

She raised her eyes, looking up at her surrounding, only to realize everything around them was burning, "What the hell…happened."

A few minutes before Ai woke up after Tengen, Tanjiro, and Zenitsu had managed to combine their forces to almost defeat the Sixth Upper Demon, when everything changed.

Tanjiro, who, after months, had been able to master some part of the Sun Breathing Technique, could be said he was reaching the same level as the Hashira, but the fight ended too soon when Tengen Uzui was the one to fight against Daki.

He cut her head in one swipe, but she didn't die for some reason and started throwing a tantrum.

Tengen Uzui moved in to finish her off by destroying her when something changed. A creature, another Demon, phased through her body, coming out of inside her, but this one gave a completely different feeling than what Daki did.

Tengen cut forward, slashing it a few times, but the Demon that came out and the Daki had disappeared, appearing somewhere else entirely.

"You shouldn't be crying. You lost your head; you should pin it back in place."

'I cut her head off…but she isn't dead, and that guy, he has amazing reflexes,' Tengen shot forth, raising his swords when his eyes widened. He could sense an attack coming toward him and instinctively defended himself.

"Ah, you are good. To think you would be able to block my attack."

"You have such a nice face…your skin is good too. No stains or marks or scars…."

"Hinokami Kagura! Raging Sun!"

The Demon, Gyutaro, stepped back from the sudden attack, but the fire still managed to leave behind a scar on his shoulder, making him pull away, growling as he looked at the boy with a scar on his forehead.

"Shut up! You will pay for what you did to Ai!"

"You said flashily!" Tengen kept the sword on his shoulder, grinning, "This is the end for you two!"

Daki stood up, and her neck and torso became one again as she scoffed, "Heh, I'd like to see you try.

And so, this led to a battle between the four, a battle that caused much damage to their surroundings, and with the bombs that Tengen threw around, it was burning, even when Ai woke up.

She held her throbbing head, dragging herself a few steps outside until she was on the street, hearing the crashing sounds, raising her eyes to dart around until they stopped on top of a roof.

The flames were burning brightly, wrapped around the sword's blade, slashing the sashes from Daki, 'Then who else is fighting?'

She turned her eyes towards where the sound of bombs was resounding, making her turn her gaze towards the right side, on the road, finding Tengen, the Sound Hashira fighting against a muscular demon with black spots over his body.

'Where are those two?' Ai breathed in, 'Total Concentration: Wood Breathing Constant: Formless: Enhanced Senses."

Ai closed her eyes, sensing four directions, but she didn't find any. She shut down her senses, turning from the above to below, and rather than all directions, she focused downwards, expanding her range to nearly half a km.

'There they are…I thought I noticed a network underground.'

Before Ai rushed in, she remembered something she had to do in this fight. They came so far to search for an Upper-Rank Demon because they had to send a message when they heard loud and clear, one that forces the Demons to attack.

(System, do we have the minimal energy to do it?)

[Yes, the energy collected has met several thresholds. You can safely use two Forms.]

(Did you say several? Didn't you say it would barely create enough energy for one form at this fight level? And that too barely?)

[The User is fighting under exceptional circumstances. Because of the unique conditions, the energy that the system gains are vastly superior.]

(What condition?)

[System doesn't have enough freedom to answer the question. It is requested that the User helps System gain more control.]

(Geez, whatever, help me perform that Breathing Technique when I see it.)

[Yes.]

"Wood Breathing Technique: Fourth Form – Wood Clones."

Wood rose from the ground, wrapping around the blade of her sword before she raised it, dragging a tree out of the ground, and from that tree came out.

Ai ran her eyes over the clone. Like her, the clone was wearing long-sleeved yellow kimono, with even longer golden-blonde hair and one visible green eye, grinning, "Yo, hotness. Can you handle the underground mess?"

Her clone looked over her shoulder towards the fight, "Can you handle that alone?"

They grinned, putting their hand on the swords, focusing forward, and speaking simultaneously.

"You have to ask?" "You have to ask?"

They passed by each other, with Ai storming towards the Demon that gave Sound Hashira so much trouble.

She slammed the Cursed Sword downward, only to be blocked by the Demon's Kama, "Another one…another one…and you are pretty. But not as pretty as my sister."

"Really? I just got a good look at myself, and I do look pretty hot," Ai grinned, pushing the blade of her sword forward.

"You awake!" Tengen took a few bombs, ready to throw when the Demon nimbly jumped back, shoving his legs forward, smacking in their stomach, hurling them back.

Ai twirled in the air, landing on her feet, "That's tough. I can't believe you have been fighting one for so long."

Tengen was on his knees, gasping, with blood covering his face, "Barely. How are others?"

"Tanjiro has been managing to hold his own, and the other two are underground with your wives. That leaves two of us to deal with this guy."

"Can you keep up?"

Ai chuckled, dodging the Kama that came flying towards her, "As if there is any doubt."

She shot forward, and Tengen turned to slam the Kama, "I can hear it!"

Ai slashed downwards, "Wood Breathing! Fifth Form! Fall! Great Tree Spear!"

Gyutaro the Demon looked up, only to feel the sound and a shock coming from the hit. He glanced down, seeing a wooden spear piercing through his stomach, and started laughing, "Hahahahahah!! That was a neat trick!! Neat trick!!!"

He twisted to cut the spear tree apart, and then he planned to move forward to cut her apart, but his Kama's stopped, barely cutting halfway through.

He looked down in shock, "It didn't cut…?"

'There seems to be a flow…not only did it take away the strength from the Kama, but it also made this thing stronger. I need to adjust.'

"Are you busy thinking something?!" Tengen dropped the bombs in front of Gyutaro's face.

"Sound Breathing! Fifth Form! String Performance!"

He held the sword in a reverse grip and spun them with the chains, slashing the bombs apart, creating a large explosion as he managed to cut his hands, legs, and even his neck of Gyutaro apart.

"How….how did you manage to cut off my head?"

Ai rested the broadsword on her shoulder, looking down at Gyotaro's head, "My Wood Breathing…it doesn't just trap Demons…it also takes away their strength and defenses. You thought you couldn't cut the stump apart because there was an energy flow inside it…didn't you?"

She tilted her head, smiling, "Sorry to say, it's because I took away your strength."

Gyutaro's head fell on the ground, rolling on it, as it said, "Ah…you…you are a talented one, aren't you? You must have been born in a good house…loving parents…everything."

Ai stepped closer, crouching in front of him, and nodded without denying, "Yes, that is it. Rather…I could say I am the most talented, gifted person in the universe, maybe in more than a single universe, before I have even awakened fully. My parents… adore me; there is nothing they wouldn't do to ensure I have a good life. And let's not talk about the rich…I had things that money couldn't even buy."

"I hate you!!! I hate you the most! I will!! I will kill you!!!"

Ai patted his head, smiling at him, "But you know…No, I am sure you do. The World…it's an unfair place. Some wish for a single talent, a single one, something that could give their life meaning, and yet have none. In envy, they can only watch others squander their talent away and complain as if they have it hard."

She chuckled, "Then there are those who keep working hard for years and yet aren't rewarded, then there are those who barely try and get more results than they wish or deserve."

"There are like me…those born with everything possible…against those like you…who are born with very little. But you know…there are some even below that…?"

"Huh? There is no one! No one is lower than us!!! We were born with nothing!"

"No…there were those, I am sure there were, they had nothing, but they worked hard. They tried their best to live their life, earn, to have a family of their own. Maybe even they found happiness…but what happened? Their life and their happiness were taken away, for no purpose, for no grand design. The only reason for their death was that someone like you…felt like killing them. So their hate…their swirling hate, sadness, and bad luck…when I think about it…my pity for your circumstances…."

"It just isn't there anymore," Ai raised the broadsword, slamming it back towards his head, but he grinned, taking back his head and putting back on his neck.

"Hahahahahahahahahaha, they have the right to hate me!! And that way, I have the right to hate and kill you!"

"Well, that's true," Ai breathed out in relief, "Since they aren't here anymore…let me carry their hates and curses."

"Hehehehehe!! We'll see how long you survive; one of you is already down," Gyutaro licked the bloody blade.

Ai didn't even need to look over her shoulder at Tengen Uzui, "I know already…he has been poisoned, hasn't he. If I went to heal him, then you would likely kill me. So…let me show you something that even the Demon King will dread."

(System Start)

[Activating Higher-Order Breathing Technique]

[A Combination of Sun, Wood, and Curse will lead to a Higher Order.]

[Calculating the Optimal Path to the Higher-Order Technique that the User Desires.]

[Path Calculated]

[Simultaneously Activating Sun Breathing and Wood Breathing]

[Activating Life Breathing Technique]

Ai coughed, feeling a raging torrent of life in her body. She never thought she would feel so close to death when so much life was in her.

[Simultaneously Activating Curse Breathing and Life Breathing]

[Karma Breathing Technique…Activated.]

Her breathing changed, and black mist got sucked into her mouth, changing the bright aura that she was always surrounded with, and what replaced it was a bottomless cursed aura, though strangely there was bottomless life too, so much that flowers grew around her, those who were injured started healing.

Trees rose from the ground, surrounding them, with ghostly faces on the stumps, screaming, causing even the Demon to tremble, looking at the girl with dark curse mark spreading over her hands, her face, over her left, green eye, turning it scarlet, "Now, you face Karma, itself."

"Karma?! Karma?!!! There is no Karma in this world!!! If there was!! If there wassss!!!"

Ai raised her broadsword, and tree roots appeared from the ground, wrapping around her hand and sword as she rushed forward, "Now there is!!"

"First Form! Significance!!!"

"Rampant Arc Rampage!!!!!!!!"

Gyutaro created a dome-shaped sickle to defend against the attack, even though he also wanted to attack. It might seem like he had lost his cool, but he didn't want to try it; he wasn't sure what the effect of this new Curse Breathing that he hadn't heard about would be.

"HHHHHAAAAAAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"

Ai slammed the blunt sword down, colliding against the dome, which broke short, and a significant slash appeared on Gyutaro's body.

Something happened in five different places at that exact moment, which shook the whole Demon Kind.

Near a fishing village,

A pot shook widely before a colorful screaming ghost ran out of it, screaming, "Ahhhhhhhh!!!! My chest!! My chest!! Who hurt me!!! WHO HURT ME!!!!!!!!!!!!!!!!!"

Inside a ruined hut,

A demon with the appearance of a short, frail man with a skinny and skeletal body, covered with veins and wrinkles and a large bump on his head, was crouching. He abruptly screamed in fear, realizing a cut on his chest and blood was gushing out.

On top of a mountain,

Azaka opened his eyes with a cut across his chest but was much weaker than the other three before him. He glanced down, confused, and then a bloody grin appeared on his lips, "Hhahahahahahaahahaha!! Whoever you are! I am coming for you!"

A Temple,

"Ahhh, so delicious, these women, pure and delicious," A young and tall Demon lay on the comfortable couch, leaning back, smiling on his lips.

He abruptly stopped when blood gushed out from his chest, covering the arm that he held in his hand.

He tilted his head, "Hm? What is this? What happened just now?"

Infinite Castle,

A Demon with pale skin, a tall and muscular body, and long spiky black hair with red tips opened his eyes, tracing the cut on his chest, which could barely be called a nick.

"Oh, a Demon Slayer…I wonder how that man will react to this."

Entertainment District,

"Ahhhhhhhh!!!!!!!!!!!!! Ahhhhhhhhh!!! Why!!!!! WHYYYYY!!!!!!!!!!! WHYYYYY AM I INJUREDDDDDD!!!!!!!!!!!!!!"

Tanjiro took a step back, glancing in the distance, where numerous trees covered in the black mist had covered an area. He could tell the power emanating from there, and he smelled the blood coming from there, but why? Why was Daki hurt as well?

He took a step back, only to realize that Gyutaro was here when the roof below them shook, and trees came out, covering the house, and black mist covered them.

"Sister!"

Ai appeared before him, slashing the sword sideways, but stopped near his neck. She moved back, taking the distance between them, standing beside Tanjiro.

"How long can you hold on?"

"Not long," Tanjiro gasped for breath, breathing, calming himself.

"Good, because I won't be able to for long…finish them off."

"Me?"

"No," Ai laughed, "All three of you."

"Hahaha! Of course, we will!!!"

"Will do."

The two figures landed behind them, wearing a board's head while the other was sleeping while standing.

Ai chuckled, meeting with the angry eyes of Gyutaro and Daki, "You see…Karmic Breathing… its 1st Form is Significance. It's above any Breathing Technique…it's a Law."

"What did you do?! What did you do!!" Daki screamed.

"The Law of Significance States – Everyone single one of us contributes to the Greater Whole. We all play a part in contributing to the Highest Good of the World."

"When I used the First Form, I set the who plays what role. Your Injuries play a role in Defeat a Greater Whole, and the First Greater Whole would be Upper Six Demons. The Role of My Injuries is to Kill you, and The Upper Six Kizuki as a Whole!"

"Impossible!! How could a human!! A mere human wields power like that!"

Ai took a sharp breath, activating the SECOND Karmic Breathing Form, "Didn't you hear me when I said?! I am the most talented, most gifted person in the whole universe!!!!!!!!! Right now!! I embody the Karma itself!!!"

"Daki!!!" Gyutaro appeared in front of her, but the massive wooden sword, which didn't have a single sharp edge, cut their heads apart effortlessly, separating them from their neck.

They didn't have a single moment of resistance when that happened.

Ai gasped for breath, and the curse that covered her body started returning to the world. She was still alive because the System took the backlash, and the only backlash she had to handle was from her Wood Breathing.

Her knees buckled, and her eyes became blurry, she could tell the others were saying something when they picked her up, but she wasn't sure what it was.

A hot blast hit her face, forcing her backward, sending her rolling back. She felt a sharp pain in her head and lost consciousness.

Even though she felt being inside her body was gone, she still felt she could open her eyes. But she wasn't in the Entertainment district when she did, she was in nothingness, but she wasn't floating. It was like she was lying on the softest bed, and her head was resting on a thigh, the most comfortable one.

"Father, for someone who exiled his daughter, you often come to see me."

"What can I say," The warm, charming voice smiled; even though she couldn't see his face, she could tell he smiled, "My dear daughter treats her life as nothing, always on the verge of dying. So I have to come and see her."

Ai, relief, "Maybe it's because you keep coming to see me that I keep trying to die?"

He chuckled, "If only it were that…then I wouldn't have to worry about you so much."

Ai raised her hand, looking at the back of her palm, wondering, "Father…is there something I am missing? Did you do something?"

"Not at all. The truth is…."

"Is?"

He chuckled, "You have to figure it out for yourself, love. Although, I did see a possibility…the path you are walking at. You'll figure it out soon enough."

Ai softly smiled, putting her hand back on her stomach, "Papa…can I ask you for something."

"Love, you know…mostly, you talk to me so sweetly when you are about to ask me if you can punch me?"

Ai pressed her lips, holding the grin off her face, "Can I?"

He chuckled, putting down a scarlet orb beside her, "Alright then. Suppose you can make it back to me. Then you can punch me."

"Papa…"

"Hm?"

"Since you put it in my field of vision, you already know I will ask you what it is?"

"Hehe, that's the System. I was checking where it went wrong to make a better-controlled one. After all, you are not the only troublesome child I have."

"Can't you take back the control? It would be easy for you, right?"

"Hm, it is. But for that…I'd have to crush your precious feelings…I might be a cruel father, but not cruel enough to forcefully crush my daughter's wishes, right?"

Ai took the palm of his hand, placing it on her cheek, "It's so warm…."

"Silly child."