It has been three years since she has been reborn into a new world. This world was not just a world she remembers, this is a world she had favored the most.
Demon Slayer.
An anime that she had fallen in love with. One that was filled with blood, losses, and some good moments. But now she is a part of it. Her name is now Willow, given to her by her mother. Her real name, her old one, was long gone, left behind in the void with her body. Here, she was reborn. A child with purple eyes with subtle cat-like pupils and black hair with red tips almost like her father when he was human, and tan skin just like her mother.
She was the daughter of a demon.
Kokushibo.
Upper Moon One.
Her thoughts wrapped tightly around that name like barbed wire. In the world she once knew, Kokushibo was a monster. A tragic figure, yes, but one bathed in blood and steeped in the loathing of his brother. The second most powerful demon beneath Muzan Kibutsuji himself.
Now is her father.
In this timeline somehow he had fallen in love with a woman. A quiet, gentle woman from a distant land, with strange accents and soft lullabies. She had been the sun in their home, singing while she cooked, weaving flowers into Willow's hair, brushing Kokushibo's cheek with a smile that softened even the deepest shadows under his eyes.
But that light had long gone out.
It happened months ago, and the memory still burned.
A flash of fire. Screams. The furious roar of a mob.
Whispers had spread in a nearby village. Stories of a demon living too close. Too dangerous. Too inhuman.
They came during the day.
She remembered the way her mother's hands trembled as she kissed her forehead and shoved her into Kokushibo's arms. "Run. Protect her. Please."
The last thing Willow saw of her mother was her standing tall at the doorway, holding it shut with her back as the villagers surged forward. Then flames. The smell of smoke choking the air. Her father had stood underneath the trees far away for far too long, staring in disbelief as the house crumbled. Willow, only barely able to speak, had tugged at his sleeve through her tears, whispering "Papa.". That was what finally broke him from the trance, and they vanished into the forest.
Now, in the present, Willow sat quietly beside him on the cool stone floor of the hidden cavern they called home. Her tiny hand rested on his knee. She was only three, but she understood more than most her age ever could. She knew grief. She knew guilt.
She looked up at her father. He said nothing. He always said nothing about that day. His face, once scarred and impassive, was now something hollow. But when he looked at her, there was always a flicker of something behind his six eyes. Something fragile.
She sniffled, wiping her nose with the sleeve of her kimono. In her thoughts, she whispered, " Mom… I'm sorry I couldn't save you. I miss you so much it hurts. "
And even if he won't say it, I know Dad misses you too.
Even if he's a demon. Even if I'm half of one… he loved you.
And I'll be strong. For him.
Even if I'm just a child.
She leaned into his side, and after a moment, Kokushibo's hand came to rest gently on her back.
They sat in silence, two shadows mourning the same light.
______________________________________________________________________________
The moon had risen, pale and cold over the treetops. Inside the cave, shadows stretched long and still, broken only by the flicker of a small flame trapped in a lantern.
Willow sat near it, her legs tucked under her as she watched her father tie the last knot of his long sash. His swords rested on his hip like part of his body, silent as breath. He glanced down at her with his emotionless mask, six eyes unreadable.
"I'm going out," Kokushibo said quietly, his voice low and smooth like distant thunder. "Stay here."
Willow nodded, lifting her chin just slightly. "Ok, Papa. "
His eyes lingered on her a second longer, and then he vanished into the night, swallowed by the forest like mist. She let out a soft sigh and leaned back against the wall of the cave. The silence around her wasn't lonely anymore. Not really. She'd gotten used to it.
Being reborn came with… perks.
The Witness hadn't given her super strength or the ability to punch through mountains, but they had given her something else. Something subtle. Something priceless.
Languages.
She could understand and speak any of them—just by thinking about what language to use. She remembered how, as a baby, she'd listened to her mother sing lullabies in a tongue that her perk was able to recognize almost instantly. By the time she was two, she could respond in perfect Japanese, English, Latin, and even spanish.
"How convenient is that?" she muttered, smiling to herself.
Then her expression sobered, and her thoughts shifted toward what was coming.
The timeline of Demon Slayer wasn't exactly flexible. The fates of those she'd come to love in her past life were marked in tragedy. And unless she acted, they would unfold exactly the same.
First would be Rui.
Lower Moon Five. The child who wanted a family so badly, he accidentally destroyed his own and later in life had created a new one that is anything but a real family. Her chest aches when she thinks of him. "I'm definitely saving that poor kid." she whispered.
But Rui was only the beginning.
The real pain hit when she remembered the Flame Hashira.
Rengoku.
Her favorite.
She could still hear his final words echoing in her memory, his bright eyes fading, blood soaking the earth. He'd died a hero, impaled by Akaza's fist through his chest. She clenched her tiny fists at the thought.
I won't let him die. Not again.
Akaza… she couldn't just fight him head-on. She knows it would not be that easy. But maybe… maybe she could plant a seed of doubt. Something that could take root in his mind. She had years to plan.
And then there were Daki and Gyutaro.
Upper Moon Six. Siblings twisted by pain and survival.
She didn't know how yet, but she wanted to try to save them. Maybe if she reached Daki and earned her trust by getting close to her. Then there would be a chance she could pull them away from Muzan's grasp. Maybe they didn't have to die.
The other Upper Moons, though… that was complicated.
Upper Moon Five, Gyokko? Absolutely not. That thing was deranged both in life and in death.
Upper Moon Four, Hantengu? Equally twisted. His human life was filled with cowardice and cruelty, and demon life had only made him worse.
She crossed both of them off the mental list with a sharp shake of her head.
Then… there was Douma.
Upper Moon Two.
"Maybe." she grimaced.
He had been revered as a child, worshipped for his rainbow eyes and never had a real childhood. Doma was also apathetic, being entirely unable to understand and feel human emotion. But that didn't excuse what he became. He feasted on women. He also killed Kanae Kocho, Shinobu's sister and one of the most beautiful souls in the manga.
Willow frowned. Then relaxed.
" Welp. That would be a problem for future me. "
She pulled her knees to her chest and rested her chin on them, staring at the glow of the lantern. Saving them all wouldn't be easy. But she didn't come here to watch people die. She came to change the story.
Even if it meant rewriting fate itself.