Yandere MHA x reader one shots

Siblings scenario

This is not romantic in any way at all

Ages will vary between characters
Your age is written after the character name

Bakugou: 8

"Stupid jerks, stupid meanies need to shut up how dare they, those bakas" you mumbled as you walked in your bedroom door and threw your backpack across the room
The whole family were natural outbursts waiting to happen, including you.
Of course you kept your outbursts to yourself much like your father did
But that didn't stop Katsuki from putting his ear up to the thin walls and litsening to you get mad
"Those idiots, that rock hurt, who throws a rock at someone for a stupid hero card" you grumbled out
You were supposed to have come back with a decent collectable card but you ended up getting your but kicked by a bunch of older grade kids about 2 grades older than you.

You scoffed while crossing your arms and legs with a pout. Your head still sit of hurt from where you had a rock thrown at you and you sighed as you looked at the ground
You heard a slight knock on your door and you grumbled at it before telling the person to come in
"Oi, bugger what the hell happened to getting your cards" your big brother walked in calling you by his usual nick name for you and you just turned your head
He sighed and sat down next to you
"Don't ignore me, keep doing that and I might not take you to get your cards back" he said and you slightly turned your head making him notice the newly forming bruise
"Did those kids do that to you" he said and you hesitantly nodded
He grumbled out incoherent words while he stood up with his teeth grit
He suddenly picked you up despite you being to old and threw you on his hip while stomping down stairs and making you put your shoes on before picking you up again despite your protest.

...
Outside the shops you saw the 5th or 6th graders that threw rocks at you for your cards and you pointed them out to Katsuki.

He growled at the sight of them before walking over to them and setting you down
"Oi, I heard you messed with my sibling, you have five seconds to give the cards back and beg on your knees for forgiveness" he growled at them while little crackles left his hands
"Oh yeah and what are you gonna do, litsen to them cry before telling us to apologize again" one of them mocked and Katsuki growled at them
"1" he said while taking a few steps forward making the others laugh
"2" he stretched his fingers with a few cracks while the others just laughed more
"3" his hands started to smoke and the others stopped laughing to watch
"4" his hands sparked a bit making the kids whimper and back away in fear
"5" he said while glareing at them and a big explosion went of in his hand while the kids screamed and dropped the cards.

You sniffled on the verge of tears because your brother had managed to get your cards back after spending a few weeks worth of allowance on them
He slowly picked them up before turning around and handing them to you
"Don't let people take them again stupid bugger" he said while ruffling your hair
"Thanks" you said
And he smiled at you, a smile that he only gave to you
"Of course, and remember just like last time I protected you we keep quiet okay" he said
You hesitated a bit but spoke out "but... There wasn't any blood this time" you said and he just nodded "but we still have to keep quiet okay" he said and you nodded

...
...

Shinsou: 18 (older sibling)

You walked in the door with a pep to your step and you saw your younger brother sitting on the couch with a curious face
"What's up with you"?" He asked and you just laughed in joy
And he definitely knew
This happened every other month
You would get a date and say 'this ones different' but he wouldn't allow it
Not this time
Not any of the other times
Not ever again
"Who is it?" He asked and you plopped down next to him on the couch to watch the show that was currently on.