(This is an AU for sci O_o. I feel really confused about how I thought of this lmao. See if you can spot the crossover :P. Ps- wrote this while I was sick and wrote it instead of sleeping :D )

Sci sighed softly as he sipped on his coffee, him turning back to the paperwork in front of him with a tired gaze.

He wasn't actually 'tired' , but more or less exhausted. He's been up almost for 3 days straight with no rest, and his hourly coffee wasn't helping wake him up as it usually did.

The worst of it was his 'father'.... He hasn't stopped staring at him for the past few hours and it was starting to irritate the scientist to no end.

"Can you stop staring? It's rude, jerk.", Sci huffed, sending a glare towards the mirror his so called 'father' was stuck in.

Well, not really stuck... It was the only way the old doc could interact with anything so he stayed close to mirrors. And he won't let Sci throw any out so that out of the possibilities.

"Staring? I'm not staring. I'm observing. There's a difference, Sans.", Gaster mimicked Sci's huffed, giving a deadpan look to the other.

Sci rolled his eyelights, going back to his work," what ever helps you sleep at night, old man. And I go by Sci now, not Sans."

It was silent for a moment before Gaster spoke up again,"... You may not like the name I gave you but it IS still your name, you know. Others know you by sans as well. So why not keep it?"

Sci gritted his teeth, his hand gripping the pen he was writing with tightly," Oh, I don't know, maybe because I was forced to have that name? You stole my original name from me.. So I don't like the one you gave me. It's simple really, I thought you were smarter than this."

Gaster barked out a laugh, it sounding a bit distorted," Oh, your funny, Sans. If I hadn't brought you into my home and changed you, you would've never been able to reach your full potential.."

Sci zeroed in a glare at the mirror, his expression filled with a simmering rage,"... You say that as if you cared... Which you didn't, I know that for a fact. The only thing you did was make me your 'perfect' son while your real one was neglected due to things you thought were 'issues'. I still hate you for that."

Sci then smirked, leaning back in his chair,"... Well, I can thank you for one thing. With out... This skeleton form you made me, I wouldn't have possibly been able to have the friends I do now. Not in this way at least. Well, I'm not gonna thank you for it because of how much of an ass you are."

Sci could tell he hit a hard point with the old Royal scientist. Gaster absolutely loathed when Sci brought up how poorly the old skeleton treated papyrus when the skelebros were younger. Sci took great joy mentioning it just to get on Gaster's nerves..

Gaster snapped," Oh shut up. You know nothing about how I though during that!"

Sci rose a brow," Oh? I thought it was pretty obvious every time you called Papyrus stupid. You kept on and on with those little nicknames... Do you know how much it hurt him? How much he only wanted his father to love him only for him to be insulted over and over? Bet it felt fantastic for you when papyrus cried-"

Gaster yelled in anger, slamming his fist into the mirror from his side," SHUT THE FUCK UP!" The slam was loud enough to shock Sci into silence, the short skeleton staring in surprise at Gaster.

"YOU KNOW NOTHING, YOU UNGRATEFUL LITTLE BASTARD! NOTHING!", Gaster growled out in anger, his eyelights flashing purple.

It was a tense silence after that, neither speaking a word. The coffee was now forgotten, Sci's hands clenched tightly as his eyesockets were wide. That was.. New. Gaster never got that angry, always managing to keep his composure.

What had Sci said that set off the old man? Whatever it was, Sci needed to be more careful. Couldn't risk anything.

"WHAT I DID WAS MAKE PAPYRUS STRONG! YES, THERE WERE INSULTS, BUT IT WAS FOR THE BETTER! THE ONLY REASON YOU WERE BROUGHT INTO THE PICTURE WAS BECAUSE I NEEDED SOMETHING TO BECOME THE SON I HAD WANTED! PAPYRUS WAS NEVER GOING TO MAKE IT AS A SCIENTIST, SO I FUCKING IMPROVISED WITH YOU.", Gaster ranted, eye twitching angrily.

It was silent once more, thousands of thoughts flooding his mind after that. He made sure to not let his emotions spiral, in fear of Dream or Nightmare popping in unexpectedly to check on him. Then again, those two barely paid him any mind , even on his bad days so he couldn't be to out of luck for it.

Gaster took a deep breath before continuing after a few minutes," Seeing as you were just a robot, it was easy to grab you without your creator knowing. That little brat you called a 'sister' was harder to shake off... What was her name? 'Roll' was it? Whatever the case, I chose you of all things because robots can be programmed, updated, remade into what the beholder chooses... I didn't realize the old coot gave you free will and a conscious.. And the need for 'eating' and 'sleep' as you call it."

Sci's eyelights glowed dangerously,".... You... 'Improvised'....? You kidnapped me on a FUCKING whim.... Just to realize I was an actual person wether you liked it or not..? That's hilarious. Really, it is.... And another thing, that 'old coot''s name was Dr. Light and he was a better father than you EVER would and will be... You know what, I'm leaving. There is a meeting scheduled with the council anyways... Might as well get there early for once.. Bye, jerkface."

Sci flipped Gaster off, Gaster's eyesockets being blown wide by the act as Sci pressed the button on the teleporter he made for special occasions.

He was teleported into the main corridor of the council meeting hall, feeling like a weight had started weighing down on him. He needed to not cause anyone to realize just how angry he was..

Sci took a deep breath, his expression going back into what he called his 'stage face'. It was essentially the expression he used that covered any emotions that could possibly be shown on his face... It helped conceal his emotions quite well.

After another deep breath, he smiled and made his way into the council meeting room, stopping by the coffee pot for a cup...