* this is an alternative timeline chapter and it does not have anything to do with the current plot, it was made as a 200k special with the purpose of showcasing what would happen if Y/N were to be turned into a demon, just a friendly reminder since I noticed that some of my readers thought this was the book ending lol

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The Demon Timeline

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Y/N breath was heavy as she ran away.

In a single moment of distraction, she ended up being abducted by a demon and brought under Muzan's grasp, she managed to escape before he could lock her up forever in some random dungeon, god knows how she managed to do it, but....

She could feel it. His blood. His cells mixing over with hers, destroying every single bit of humanity in her body.

No.

This can't be happening!

If she loses her human memories, she won't be able to go back in time unless a demon slayer kills her! But she knows. She knows that Muzan won't let it come to that, when the transformation is complete, he will make sure to restrain her from any outside interaction, even if she would only be one more of his minions, he would still be careful with her.

She contained a relieved sigh when she finally saw the recognizable entrance of the butterfly mansion, a group of people were outside with lanterns, probably looking for her.

For how long she was missing? She couldn't tell.

"She's here!"

As they saw the weakened girl walking silently in the direction of the house, Tanjiro didn't waste time in running up to her, grabbing her shoulders before she could fall to the floor.

Y/N rest her forehead against his shoulder, Tanjiro could feel her hot breath against his neck, but most importantly, he could smell it.

The familiar smell of the creatures responsible for all of his suffering.

The smell of a demon.

He didn't have time to question her about it, since he suddenly felt a sharp pain, and then, gulping sounds coming from his neck.

"S-she's biting him!" Kanao exclaimed, Shinobu quickly ran up to them, harshly pulling Y/N away from him and starting to shook her with a pained expression.

Tanjiro just looked at her in shock, entirely ignoring the pain and the blood dripping from his shoulder, his eyes were locked on hers.

The dried tears in her cheeks, his own blood dripping down in her chin, the way that her humanity still glistened in her eyes as she looked at him with a guilty expression.

He could hear some people talking to him, asking him if he was okay, but it all sounded like a buzz to him.

This couldn't be happening.

A cloth was pressed against Y/N face, and she passed out.

『••✎••』

It has been some days after the attack, Y/N was locked up in the basement, but the weird part was that...the demonization wasn't advancing.

But it wasn't retracting either, they all came to visit her everyday in hopes of a change, but all they could see was her sitting on the floor with glossy eyes.

She looked like a doll. Or even worse, a dead person.

She wasn't eating human food, and even when they risked offering blood to her, she also didn't react.

Was it really her resisting the demonization, or it was another thing?

It was another day... another gloomy day. Shinobu came to bring her food, even though she knew that she wouldn't eat anything.

"... Now I know why this is happening...." Y/N silently spoke up, sitting in the corner while hugging her knees, her wrists and right leg shackled.

"Huh?" Shinobu eyes go wide, it has been so long since last time she heard her voice.

"This is happening because I can't do anything right. I'm so useless. My existence. My efforts. My wishes. All of it is useless."

"Y/N!" She quickly got close to the girl, resting her hands in her cheeks, even though she knew very well how dangerous this action was.

"Compared to everyone else in this universe, I'm so small. I'm not a character nor a living being anymore, I just....simply don't have a purpose at all."

Some of her tears splashed at Shinobu hands.

"I... I just wanted someone to tell me that I'm doing a good job..... I'm trying.... I'm really trying.... Why? Why? why? why? why?!"

Red patterns started to slowly appear around her body, her eyes slowly changing to a bright yellow color.

"Please stop! The demonization is progressing!" Shinobu hugged her tightly, crying loudly in her ear.

She then finally looked at Shinobu, her eyes glossy.

"Shinobu...please don't die..."

"I'm not going to!"

Y/N just cried more loudly after hearing her statement. "Liar!"

"I'm not lying! I promise!"

"Sanemi....Iguro....Mitsuri....Gyomei...Muichiro..... No... No...NO! Please, please stop! I can't take anyone else dying anymore!"

"No one is going to die, they are all fine!"

The red patterns kept appearing, until a ear piercing scream came from Y/N.

Shinobu quickly stepped away from her, the loud sounds attracting the others.

She just kept screaming and trashing around, blood starting to seep out from her chained wrists.

Some of her tears splashed at the ground as she looked down at her thighs.

"It hurts.....it hurts....it hurts so much.....ithurtsithurtsithurtsithurtsithurts...."

Tanjiro just couldn't watch it anymore, quickly running up to the girl and hugging her. "Please, you're hurting yourself, please don't do this..."

She just kept still, not reacting at all, until she silently asked :

"Tanjiro....are we....still friends? Even when I'm like this, do you still like me like you used before?"

"Of course!.... of course I do!"

"Then...will you listen to my request...?"

"I will."

He let go of her, silently looking at her eyes.

"Kill me."

"Huh?"

"If we really are friends, then kill me."

" I- I can't do that!" He shook his head. "Please...don't ask me to do that!"

Y/N didn't have time to convince him, as the demonization came back again, she started to scream even more loudly them before, trashing around as the previously healed cuts from her wrist came back.

"PLEASE KILL ME! I CAN'T TAKE THIS! NO! NONONONONONONO! IT HURTS! I HATE PAIN! I HATE PAIN! I HATE PAIN! KILL ME! KILL ME! KILL ME! KILL ME!"

Though he did unsheathe his sword, his hands were trembling terribly as he grasped the handle, his breath heavy as he looked at the person who once used to smile every day at him.

Someone so important to him...someone that he cared so much about....and now, he would have to kill her with his own hands?

The others just looked at them in shock, no one knew what to do or how to react.

The decision of killing or risking her killing others was completely on Tanjiro Kamado shoulders.

It's so unfair...of all people...why she?

All she ever wanted was to help people, he knew that because of how long they have been together.

Always looking into other's wellbeing, always ignoring her wishes...

If only they had more time, then maybe, he would have been able to understand her more. Why didn't he try to get closer before? Why did he leave her alone?

Is it his fault?

Perhaps....maybe in another life... they could've been happy.

Not only him and her, but everyone else.

She did say that before, didn't she? That she wanted to spend more time with everyone.

But now, all that was left was a promise that wouldn't be kept anymore.

It was the last thing that he thought, as he made a clean cut across her neck.