Undertale AU Sibling Oneshots

Overprotective! Error x Young! Sister! Reader

Requested by the lovely BrightFire123!~

You giggled and squeaked happily as Error swung you around in his strings, slowly raising you higher before bringing you back down into his arms.
Originally, Error would've seen you as just another anomaly in the multiverse, but now he can't imagine a day with out you.
You giggled at him, batting at the glowy blue strings around you both.
"AlRiGhT, (y/N). I nEeD tO gO fOr A wHiLe, BuT i'Ll Be BaCk, OkAy?"
"OkAy!" You beamed up at him, letting him set you on the white floor before he disappeared into one of his portals.
Some time passed, you keeping yourself busy with various toys Error supplied you with. You perked up to the sound of a portal, and with a happy gasp you jumped to your feet and ran to it.
You slowed to a stop however, seeing that the skeleton coming from the portal was most definitely NOT Error. He spotted you, momentarily distracted from his portal slip up.
Your eye sockets were wide, pupils sparkling. You'd never seen anything so colorful.
"Uh..." The colorful skeleton stared down at you. "H-Hello?"
"hI!" You chirped, running up to him.
"Who are you?"
"i'M (y/N)!" You grinned, bouncing on your tiptoes.
"I'm Ink. Do you know where Error is?"
"uH-uH!" You shook your head.
Ink hummed, looking up when a portal opened.
"(Y/n)!"
You giggled as you were suddenly yoinked back, laughing without a care as Error cradled you.
"DiD hE hUrT yOu!?"
You shook your head again, still giggling. Error let out a glitched sigh of relief, using his strings to lift you into the air, keeping your thoughts occupied with a game.
You completely ignored Ink and Error's conversation below, enjoying the feeling of being flung upside down.

-A few year time skip-

"Hi InK! WrOnG pOrTaL aGaIn?" You chirped, hanging upside down from your own strings, seeing Ink step through a portal.
"Huh?" He look a little tired, probably fighting Error or some other bad Sans again. "Oh yeah, sorry about that."
"It'S oKaY." You hummed, lowering yourself down to the ground. "CaN i AsK a QuEsTiOn?"
"Sure, what is it?" Ink tilted his head at you, plopping down on the floor to rest for a moment.
"HoW mAnY cOlOrS aRe ThErE?"
Ink let out a laugh.
"There's a lot, you've got your basic rainbow and then a million shades to go with them."
Your eyes grew wide and sparkles again, that stupidly cute grin on your face again.
"I'm guessing you don't see a lot of color?"
You gestured to the area around you.
"Fair enough. If you want, I could show you other AUs."
"BuT aReN't ThOsE aUs AnOmAlIeS?"
"Well... From Error's viewpoint, yes..." Ink hummed to himself, "How about the original AU?"
"UnDeRtAlE!?"(*CinemaSins voice* "roll credits!")
"Yes! Undertale!" Ink laughed, creating a portal and holding his hand out to you. You took it with enthusiasm, letting him yoink you through the portal.

Error got back to the void a while later, sighing tiredly. But even in his tired mindset, you not greeting him by barreling into him at full speed caught his attention immediately.
Cause.
Y'know.
He wasn't on the floor with you on top of him giving him a bear hug.
Looking around, he eventually found a few paint splotches on the void floor.
...
"INKKKKKK!!!"

"Ohp." Ink perked up to a enraged roar that could practically be heard across the multiverse. "Seems like our playdate is over."
"AaAwWwWw..." You frowned at the news, reaching up to hold onto the multicolored Echo flower crown Ink made you.
Grinning, Ink turned to you. "I got an idea for a prank."

When Error's portal ripped through the open air and he stroke through, Ink, with an overdramatic twirl on his toe, spun and swiped his paintbrush straight up Error's front, covering him in a multicolored splash of paint.
You broke into a giggle fit, moving to begin tugging your brother, who was currently in the middle of a Windows Death Screen, back into your colorless void.
"SeE yOu LaTeR iNk!"
"Bye (Y/n)!"

(Error: I saw you hanging out with (Y/n) the other day! Ink: E-Error it's not what you think! Error: I WON'T HESITATE B—!!!)

Me, holding a clipboard: Aaalright, Ink's paintbrush, 2. Error, 0.