Gaster Blaster Sans X Reader

Part 53

My experiments prove over and over again that I have underestimated my plan. I need more than just DNA . . . I need a Soul.

I am sitting down in my old rolling chair, thinking. The lab is almost completely destroyed because of how many tantrums I've had. I think it's time I go back.

~~~~~~~

~Normal POV~

You are about to fall asleep. Sans beat you to it though, leaving Papyrus the only awake one. You tuned out Sans's mumbling. Your head bobbing and your eyes drooping. Papyrus on the other hand was sitting up straight and listening to every unclear word that Sans uttered.

You jump at a sound like ripping fabric. Shaking the sleepiness away, you look up and see Gaster in all of his black goopy glory. You poke Sans a couple of times to wake him up. He eventually wakes up with a yawn, rubbing his eye sockets.

"What?" Sans mumbles not quite sure why he had to wake up. "Oh . . ." He says when he sees Gaster, "What happened?"

Gaster pulls out some sheets of paper with the strange writing on them. He hands the papers to Sans. Sans reluctantly takes them and reads them over.

"What does it say?" Papyrus asks, starring over his brother's shoulder. Sans flips through the papers a couple of times, growling.

"No!" Sans says sternly "I already gave you a chance, Gaster. I gave you my trust! And you hand me a pile of failed results and uncertain questions. You can't even guarantee her safety, or any of our safety for that matter! So no, we won't be taking part in any more of your little experiments."

"That's too bad. You were behaving so well~" Gaster says.

Gaster's right eye blazes purple, while the left only flickers. Sans gasps, falling over and holding his left eye. You see purple and blue flames reaching in-between his fingers.

"GAAHHH! P-PAYRUS, Y/N! GET A-AWAY FROM ME!" Sans screams.

"Sans? I don't know what's going on, but I'm not leaving you" Papyrus says, stomping his foot on the ground.

Sans curls into a ball. You can see sharp ridges poking out of his jacket and the harsh crack of bones. You grab Papyrus's hand to try and lead him away, but he won't budge. Sans's form starts to change; his legs become more animal-like and a tail starts to grow.

"Fascinating! So you can control it now?" Gaster asks Sans. Sans glares at Gaster, his left eye still glowing purple and blue and his face now a long muzzle.

Sans lunges for Gaster, but the goopy mess dodges with surprising speed. Sans growls and continues to grow to his full Gaster Blaster size. Gaster's left eye flashes in a pattern, almost on a beat with music you can't hear. You notice Sans on all four legs, bobbing to his own beat.

Papyrus steps back, scared. There is a low droning in the back of your mind. It gets louder and louder, until you realize it isn't droning at all, but . . . music? Two "themes" playing at once?

Sans, now fully grown, lunges again at Gaster. One of the themes gets louder; you assume it's Sans's theme. Gaster dodges yet again. He pushes outward with his right arm, sending multiple misshapen bones flying at Sans. The other theme gets louder and Sans's theme gets softer. As the two of them fight, you start to catch on to the pattern. Both Sans and Gaster seem to have a sort of theme song that plays louder that the others when it is their turn.

Helpless, all you and Papyrus can do is continue to move out of the way of the fight. You watch every move Sans and Gaster make, flinching at the close blows. But neither of them have actually hit the other. They only seem to be trying to tire the other one out. Sans is now off beat to his theme; he is slowing down.

"Give up Sans! You know you can't defeat me!" Gaster calls "besides, I can control you, your brother, your sissy little girlfriend, even the world if I wanted to!"

Sans glares at Gaster, his head low. He is panting heavily. Sans faces you and Papyrus. His eyes are sad and his theme is very quiet.

"Wait . . ." Gaster whispers curiously.

Sans lifts his head, his theme getting louder and his eyes filled with determination.

"No . . ." Gaster says louder. His theme is getting softer.

Sans charges at you and Papyrus, the ground shaking with every stride. You turn to run away, thinking Sans is going to attack you.

"What are you doing?!" Gaster yells.

In one swift move Sans grabs you and Papyrus in one arm and claws the air with his other arm. The Void rips open. Sans jumps through, carrying both of you with him.