Undertale AU Sibling Oneshots

Cold! Error x Younger! Reader

What joy! Y'all get a rare line-less drawing! This time it's a drawing of Kris from Deltarune by yours truly. Planning on drawing Underfell Grillby next!

(Things have felt too fluffy lately between siblings, let's just get some sibling angst goin on here)
(Dont worry tho it ends happy)

Current Vibe: Agoraphobia by Autoheart

Not a request.

Error was never good with emotions. Never good with dealing with them. Never good with showing them. He just... wasn't good with them in general.
So it was quite the struggle when he found you. At the time, you were nothing but pixels and code to him, just another thing to be erased. But when his strings attached to you, he found your code hauntingly familiar.
Too familiar, almost like he was seeing a tiny piece of himself.
So he kept you alive, bringing you to his space in the multiverse, teaching you about the many, many AUs, about what he does, and about his rival and enemy Ink.
He'd noticed you paying attention to each word, attaching to him almost like how a duckling imprints on its mother.
'Annoying.' His mind hissed. He was here to do only one thing: delete AUs. Not make attachments. You were there only because he'd taken an interest to you, perhaps you'd become his successor in case something happened to him. But that was it.
Yet you persisted. You asked questions about things that weren't his job or about the different AUs. You would worm your way into his lap (much to his displeasure) whenever he watched Undernovela to watch with him, silent whenever he looked invested, and politely asking questions about the characters and plot.
You'd jump up whenever he'd return from an excursion, offering hugs to him if he looked exhausted or stressed, or giving him space if he looked angry.
You were like a little nightlight in his void, despite his plane's brightness, offering a change of view from the blank landscape that would usually surround him.
Despite your efforts, Error made no move to return your hugs, even if you persisted in them. He would groan quietly at your questions of his show, before begrudgingly answering them just so you'd quit asking. He'd struggle with you whenever you climbed into his lap, his glitches quickly making him lose against your drive to get closer.

It was quiet while Error was out. Thoughtfully, at least to you, he had left behind some crayons and paper, books, anything you could think of to keep your child mind occupied while he was out.
And yet, with all those activities laid out before you, you were more focused on the torn up hoodie Error had left behind. He had a couple, but this one seemed like a favorite.
Quietly, you had gathered scraps of fabrics Error had left for you in case you wanted to mess around with glue and glitter and whatnot, and did your best to match the colors. Once you had your fabric, you took time to cut shapes out in accordance to the tears, using the magic you'd learned from Error to stitch everything together. When you were done, it wasn't the best, but the tears were sealed and it wasn't anything that couldn't be undone and restitched with a more careful, talented hand.
Proud of yourself, you gingerly set the hoodie aside where Error would find it, knowing deep down, he'd be grateful for your attempt at fixing it.
Partway into your drawings, you heard Error portal open, and glanced up to see him stumble through, heaving and battered.
You hesitated as your feet patted in his direction. You couldn't tell if he was angry, his head was down and he was quiet.
You watched as he walked further into the void before sitting down, hunched and breathing heavily. Tentatively, you stepped up to him, resisting the urge to reach out to him, eyeing the wound to his upper arm.
"Can I helP with anythinG?" You asked softly, your voice glitching slightly from just how long you stayed with him.
"I'm FiNe." Error growled, not looking at you, using his strings to tie a broken bone in its proper placement with a pained hiss, "Go MaKe YoUrSeLf UsEfUl ElSeWhErE."
It was quiet, your footsteps padding away before quieting back down. Error let out a glitched sigh, carefully shrugging off the jacket he was wearing. He tossed it to the side, taking time to tend to his other wounds and scrapes before noticing his hoodie.
He grasped it, taking note of the inexperienced, but thoughtful stitching that lined the previous tears and the slightly off color fabrics. The tension left Error's form as his thumb gently traced the edges of your (color) stitching, a unfamiliar sting making itself known in the lower edges of his eye sockets.
He was stupid, he was sure of it. You had cared so much for him, taking interest in his profession and hobbies, respectful of when he needed space and when he didn't, even going so far as to try and stitch his favorite hoodie back together.
"(Y/n)..." he glanced back over his shoulder.
Only for his breath to sharply hitch at the sight of his open portal, and the lack of you in the void space.
"Oh No..."

Error had told you about this AU, what was it called again?
A swift kick to your stomach area was enough to bring your attention back to the present. You'd been trying to continue Error's unraveling, his strings tightly grasped in yours as you pulled at the AUs code before getting caught and beaten up.
You looked up with blurry vision, a Sans clad in black, red, and gold sneering down at you.
"Damn brat," another kick, this time to your arm, "Boss' gonna blame me for all this hell you and that glitchy freak caused!"
You coughed as another kick collided, your body rolling over in the snow as you quickly glanced around for Error's portal. The Sans' shadow looked over you, as you braced yourself for another kick—
The air above you shifted, the cutting sound bringing your attention to the blue strings that slashed above you, driving back your assailant.
A second later, you were scooped up, Error cradling you in his arms, willingly this time, and glaring at the Sans across from him.
You flinched at the growl from the Sans, and just when you thought it was over, that you'd both be speared by his attack, one of Error's portals opened beneath you, and you dropped through to safety.
Error's knees hit the floor as soon as the portal closed, gently setting you down before moving his hands to assess your aches, thumb gingerly tracing the small crack above your right eye.
"(Y/n)? ArE yOu AlRiGhT? yOu ArEn'T tOo HuRt ArE yOu?"
"I'm okaY." You reassured him, offering a tired smile to hopefully ease his panicked worry. Error took in a shuddering, slightly glitching breath, holding you close.
Slowly he nodded, scooping you up. "PlEaSe, Do NoT eVeR lEaVe To An AU WiThOuT mE aGaIn."
"I won't. I jusT wanted to helP."
"I kNoW." Error murmured softly, setting down in his favorite spot, and letting you rest in his lap. "ThAnK yOu FoR tRyInG tO hElP."
As Error opened a portal that showed Undernovela, you noticed he was wearing the hoodie you'd stitched back together.