S1 Muzan x mother reader (completed)

Extra:flashback

(This takes place just a little after the curse started appearing. The demon slayers are not yet created)

The sun sets, darkness loomed over the mountains as seconds passed by.

The tweeting of birds was replaced with crickets chirping continuously. The dark space illuminated by small fireflies that fluttered.

The Ubuyashiki family, a close relative of Y/n.

The head of the Ubuyashiki's sat on the floor with his wife. He stared at the scene infront of him, wondering if he'll miss these kinds of images and sceneries.

The curse still right above his brows were dull and smelled of rotten flesh. He closed his eyes, savoring the peace and chilly cold air.

Crumple

He opened his eyes to see Y/n, his great aunt. His eyes wide as saucers stared at her.

Her face and complexion hadn't change since he last saw her.

"Y-Y/n-sama?! I-is that you?!" He asked her before stumbling up and almost tripping when making his way towards her.

"Hm, yes. It's me" she replied, a soft smile on her face as she patted his head.

Ubuyashiki then noticed her frown once she set her eyes on the curse.

He felt awkward and shy at the mark, he pulled away and covered it with his hands.

"I-Its gross isn't it?" He asked the demoness, his eyes glancing off the side.

Y/n shakes her head and moved his hand away. "It is...but it isn't enough to make me stay away" she states before walking past him.

"H-huh?"

He turned to the demoness who walked to his balcony. She turned her head back at him with an expression he did not know.

"We have a lot to talk about, Ubuyashiki-san"

########

"What?"

"Yes. My son, Muzan had turned into 'immortal being' though he started to use the name 'Demons' as a substitute" Y/n blatantly informed him.

They both sat down, a table separating them.

"I cannot tell you much as he do not completely trust me. All I can tell you is we eat humans, we cannot walk under sunlight and that is all the info I have" she adds.

Ubuyashiki gulped, "W-well...as long as M-Muzan doesn't have ideas on k-killing and ruling the human r-race right?--" He paused once he looked into her red eyes.

Her eyes was clear, it was so clear that it felt like he was staring right through her.

"We are humans, my dear. Boundless imagination and dreams could be fulfilled with just time...and time alone..." the demoness stated, removing her eyes from the boy, her hands gripped her haori.

"W-what do you mean Y-Y/-sama?"

"It won't be long until he thinks of mass murder, Ubuyashiki" she replied to shaken boy.

Ubuyashiki clicks his tongue, all they thought that they only have to worry about a curse that basically was punishment for bearing a 'demon'. He could just not believe it.

Y/n notices his panicking figure. True, it was an information hard to believe. Yet, when you really put things together, it all made sense.

She raised her hand and hovered over the table. Two fingers outstretched and tapped the wooden furniture.

"I'll be supporting you under wraps. I will use the necklace you gave to me when you were little. It will be my sign of the 'peace treaty' or better yet, your survival are on my hands."

"Whether I lose it during battle, whether I like it or not. Once that necklace is off me will sign me as an enemy...got that?" She asked him, a kid who was given absolute information.

Burying his head in his arms. He grits his teeth. "O-ok...I a-accept..."
He hesitated.

Y/n smiles and grabs his two hands. His eyes widened at the gesture and stared at her soft delicate hands which held his hands.

"Y-Y/n-sama?..." He called out. Not knowing why she grabbed his hands out of the blue.

Her head was facing down. He didn't know what expression she made, scaring him more.

"Muzan will likely know what I did today...I wonder what he'll do when the time comes..." she wondered.

"May...god have mercy on you...Ubuyashiki...the human kind's future...is in your hands... protect them well"

His body froze. Her tone was defeated.

Despite knowing that maybe , just maybe they can't stand a chance against him. He bit his tongue

"I...will do my best...Y/n-sama..."