Undertale AU Sibling Oneshots

Underfell! Frisk x Older brother! Scary! Reader

(totally not a self/OC insert in my favorite AU)
(Might draw my new OC later)

You laid on the couch, just dozing as Frisk was curled up asleep on your chest. You two were having a lazy day on the surface, really everyone was.
It was storming outside, and since none of you had anything to do, you all decided to do nothing.
Sans was snoring away in the armchair, Frisk soundly asleep on your chest, and you on the verge of sleep.
You remember when you and Frisk first fell into the Underground, how you barely trusted anything within five feet of Frisk. Flowey managed to get a pass, warning you both of Toriel's behavior and finding a place for you both to hide.
After that it was all an incredibly slow burn to get used to the monsters. You'd worry over Frisk getting hurt, only to be proven, once again, that they can handle themselves.
When you and the monsters finally got along, Frisk was already trying to drag you further along past Hotlands.
By then, everyone knew just how scary you could get when you were pissed.
You groaned and opened one eye in response to your forehead being poked. Papyrus stood over you, expression warm.
"I'm making dinner soon."
You gave a silent thumbs up, reminding him too much of Frisk and making him chuckle.
Lifting your head, you patted Frisk awake and earning a groan in response.
"Go wake up Sans, Paps is making dinner."
Frisk crawled off of you, and you sat up to stretch.

On your way home to Toriel's, a group of humans stopped you both. They often did this, clearly unappreciative of the fact monsters were there now.
Despite them being on the surface for over a year now.
"Hey guys, look! It's them monster lovin' brats!"
You stared at them past you hair, glaring at their snickering and sneering faces.
Frisk cling to your sleeve, hiding behind you.
"Don't you people have better things to do?" You murmured, tilting your head.
"Eh?"
You grinned, lifting your head to reveal your blood red eyes.
Oh the horror on their faces was so worth the earful later.
"Those monsters may not jump to violence anymore, but if it gets my point across I won't hesitate."
You flexed your hands, red bolts of determination crackling along your fingers.
"Now get before I make you." You growled, taking a single step forward.
That was all it took, the group ran off in a heartbeat, and you held Frisk close on your way home.