Undertale AU Sibling Oneshots

Undyne x Amalgamation! Reader

(*deja vu begins playing*)

Requested by the lovely NingningPurple22!~

Despite the blazing heat, Undyne sprinted from Waterfall to Hotlands, carrying your sick person on her back.
"It's okay, (Y/n)!" She exclaimed, hearing you cough, "We're almost there!"
Undyne nearly collapsed once she got to the lab, panting harshly as she slipped you off her back and into her arms, forcing herself to stay on her feet.
"Alphys!"
The yellow lizard monster turned the corner, gasping and rushing to you both.

Your health only got worse, and Alphys was getting desperate with the other patients not getting better either. She confided in Undyne about Determination, and eventually Undyne agreed.
Everything that could've gone wrong went wrong. The patients were all melting and fusing together, including you.
You could hear Alphys' panicked shouting, and Undyne replies sounding just as frantic.
You did your best to move, to follow the sounds, but the doors were closed.
Time passed slowly, and you eventually heard their voice again, this time clearer and clearer as they nearest the door.
"U-Undyne! Wait, I don't you really want to—"
"I want to see her Alphys, e-even... Even if she's... dust. No matter what state she's in, I don't want her to think I left her!"
It was quiet for a long moment, and you barely heard Alphys' quiet "okay." before the doors began to open.
Undyne and Alphys stood in the doorway, your sister slipping past the scientist to look around the room.
You were nervous, you had melted just like the others, and you didn't want your sister to see the horrific thing you'd become.
Cautiously, you peeked over a table, seeing Undyne lock onto the movement.
"(Y/n)?"
"...Dyyynnne."
Undyne moved closer, and you shuffled out from behind the table, your small form shrinking back at her wide eyes. She slowly knelt to your height, reaching out. You let her reach for your hands, fully prepared for her to pull away.
Instead, she pulled you forward, hugging you with care, her tears dripping onto your shoulder.
"I'm sorry you had to go through this..." Undyne breathed, pulling away a bit to look at you.
"I-I'm s-sorry too..." Alphys piped up, now standing by Undyne's shoulder.
"You didn't know what would happen Alphys, this isn't your fault." Undyne reassured her.
"I-I can... Try to d-do some tests to reverse the effects, i-if you'd both be okay with it."
You immediately nodded, still holding onto Undyne's arm. Alphys was only trying to help, and she was willing to try and fix things too.
"If (Y/n)'s okay with it, then so am I." Undyne said, standing with you in her arms. It was a little weird, seeing as your form tried to melt back into the floor, but you managed to solidify your form enough to stay put as Alphys led you both to a different room.
Unfortunately, none of the tests seemed to work or show any sign of what could be done to fix things.
So you were stuck like this, but slowly, you and Undyne got used to it, spending time together in Waterfall. Overtime, you'd managed to get your face somewhat back to normal looking, but you weren't too upset over it seeing as your still goopy eye sort of matched Undyne's new scar.
When Undyne wasn't training, you'd spend time together making flower crowns out of Echo Flowers.

Me: *casually plucking your heartstrings and totally not in Nightmare cosplay* Hello.