I don't own Underswap or Undertale. Neither do I own the Gaster Blaster Sans AU. Hope you like it anyway! ^^
Chapter 4: Gaster
(Muffet POV)
I starred in shock and horror when I saw poor little Sansy cry in pain. His body had started changing, and it was not a pleasant change. Horns had started growing out the back of his head, his bone started cracking above his nose, he grew sharp, pointy teeth too, and I think other things might have changed, but they were covered by Papyrus' spare jacket that Sans was wearing. Oh, poor Sans. After some time, the blue glow surrounding Sans, disappeared and Papyrus picked him up and Sans wrapped him arms around Papyrus's neck. Papyrus then started rubbing Sans' back and Sans I think, went to sleep, his left eye still flaming blue even though his eyes were closed. Papyrus got to his feet and carried Sans to the back door.
"I gotta get him to Dad….," Papyrus said as he past me. I opened the back door for him and then closed it.
"I hope he feels better soon!" I called as Papyrus walked out into the falling snow keeping Sans close to him.
(Papyrus POV)
This has got to be literally the weirdest day of my life. What was happening to Sans?! This hadn't happened the last time he ate sugar! Well I gotta get him to Dad. Dad works at a Party store not to far from here. It's one of the only joyful places here in Snowdin other than Muffets. Dad is an excitable person, but also busy since his store his pretty busy during the day. Monsters can still be able to have joyful parties despite the loneliness of Snowdin and the rest of the Underground. It was way to spot his store, cause of all the lights. I walked into the store, closing the door behind me.
Dad, who was behind the pay counter, not looking at us, said, "Welcome to the Party Store!"
"Dad," I called out.
He turned around to look at me.
"Oh hey Papyrus, what brings you here and why do you have Sans with you? Isn't he supposed to stay inside the house?"
"Yeah, but something's wrong with him. He started changing into something. I don't know what. I'm scared for him."
"Let me see him," Dad demanded. I removed Sans arms from my neck and gently handed him over to Dad.
(Gaster POV)
It had been an unexpected visit from BOTH of my sons. First of all, why was Sans out of the house? Second of all, why is Sans' eye glowing? I can see blue light coming from him even though he isn't facing me.
"Let me see him," I demanded. I needed to see what was wrong. Papyrus detached Sans from him and gave him over to me gently. I took him in my arms. Even though Sans was 10 years old, his lack of growth spurt made him seem very small in Papyrus' jacket. I took off the hoodie from his head. I gasped at what I saw. No no no no no no no no no no! This can't be happening!
"What's wrong with him?" Papyrus asked after noticing my panicked reaction.
"I knew something like this would happen…," I said shedding some tears.
"You knew this would happen and you didn't tell us?"
I didn't respond.
"Please Dad, tell me. I'm as worried as you are about Sans, and I can't help if I don't know anything."
"I s-suppose. Well might as well start from the beginning. Remember that night when I was fight training as a Royal Guard? You were too young for me to just leave you alone at home."
"I remember that. You were fighting against that dinosaur girl. Alphys I think her name was."
"Yes, Alphys. She was young and still needed training before she became a royal guard yet. She was strong but clumsy. I'll never forget. Well while I had summoned some gaster blaster attacks-"
"Sans got lose out of my arms. I tried to follow him, but Sans was to quick going down the stairs and ended up tripping and tumbling down the stairs through the door to the battle field. I think he wanted you."
"I shot a gaster blaster blast at Alphys, but she used on of her axes to deflect it, sending the blast right at Sans. I signaled a stop to our fight after noticing what the blast had hit. I ran over to Sans in panic. Gladly, he was still alive, but he was crying and his left eye glowed blue. That's when I noticed that the blast had broken his right eye from glowing. I check his HP still amazed and thankful he was still alive. His HP was dangerously low yet, I could feel a power in him that I had never seen in him before. I picked him up, trying to heal him. By that time, you had already rushed in next to Sans, trying to comfort him since you did not know how to heal yet. I managed to get his HP back to full health, but the I could not heal the broken eye. I quit being a royal guard trainer after that, fearing you or Sans might get hurt if I left you unattended. When we got home that night. I tried searching the library for anything on what would happen if a skeleton survived a gaster blaster blast since I did not know everything about a skeleton's magic. And no, I did not create the gaster blaster, your grandparents just named me after it, cause I know you asked me a while back why my name was on one of the main skeleton attacks. Anyways, I found some books on skeleton magic and brought them home. After looking and searching a bunch of times, I found something. It said that after the blast of a gaster blaster upon a skeleton, they are most likely to either die or if they survived, they would take physical changes of a gaster blaster on their body if they allowed a lot of their energy and magic to flow through them. With this fear, I decided to keep Sans away from about learning his magic at all. I kept him locked up at home, cause if he went outside, someone might tell him about his magical ability. Also Sans can also trigger him magic and energy by sweets which will make him jumpy and can trigger what has happened now, which is the second reason why you don't give him anything sweet. Though one day, I left one of the books about magic lying on the couch, Sans had read it learning he, you, and I could do magic, but even with the new power flowing in him that he did not know of, a skeleton's first summon with magic is always the hardest, even when summoning a bone. After that it's much easier to use magic. Which reminds me, how did this happen? Why was Sans using magic? What for? Start explaining Papyrus."
Lol, looks like Paps is in trouble. Anyway hope you like this chapter! Reviews would be appreciated.