Introduction: This story is about an unlikely friendship that develops between Underfell Sans and Undertale Papyrus. The Underfell world is an Alternate Universe of Undertale based around every monster believing in the creed "Kill or be Killed" instead of being friendly. The hatred of humans is also spread throughout Underground. Killing monsters is legal in Underfell. There is no hope and no peace, everyone is on edge by the fear of another human and the hatred of human existence. Hate is the main emotion felt by everyone. Underfell Papyrus also does not live with Sans, as the commander of the royal guard he stays mainly in the castle, only visiting Sans when he has done something wrong. I know that Undyne is supposed to be the commander of the royal guard but in my interpretation of Underfell I believe she was killed by Underfell Papyrus. Underfell Sans is unable to kill others because he is split between the harsh expectations of his brother and the reality that killing is wrong. He also does have a heart for his brother and other monsters, which he secretly dreams of being in a world similar to actual Undertale. *Update 2018, first chapter created early 2016. It has been over two years, I know it seems like I have abandoned this fanfiction but I have been getting back into Undertale and I think I might finish this at some point. Sorry for making two chapters then jumping into the void, but now I have time to finish things like this so hopefully that happens at least. Or not, but we will see.
Frost as cold as the souls of monsters reign through the premises. A monster made of bone in a scruffy black jacket scouts the area, clenching his fists as he thinks of how weak he is. He puts a hand over his defective eye socket, a special present from the boss when he did not meet up to his expectation, another act of being unable to kill. He hates other monsters, he hates his weak self, he hates his brother. No, he does not hate his brother. Even though he should. Every monster for themselves, right? Every monster hates every other monster, right? As Sans patrols on the outskirts of Snowdin he thinks this to himself, looking around, watching for anything unusual.
Suddenly a small creature dashes in the distance between trees, a monster child being loud and playful. Sans' only working eye socket glows red as he summons what looked like red dragon heads, anger building up as no monster is supposed to run around after curfew.
"Hey! Get the hell out of here kid!" Sans yells as the kid continues running through the woods.
"Fuck off shit bag" the kid replies, sticking his tongue out, continuing to run.
Sans smirks showing his sharp teeth, with one tooth shining a bright gold. The dragon heads glow as Sans aims for the forest, they open their mouths then shoot out a giant red laser right next to the kid, exploding trees nearby. The kid's eyes widen as he sees the trees destroyed, then runs off in fear. Sans smirk turns into a smile, almost about to laugh, but then stops himself thinking about what he has done.
"I didn't kill him...I JUST LET HIM GO! FUCK!" Sans yells to himself as his eye and fist glow, hitting a tree with his fist in anger, "The boss is going to kill me, letting a trouble maker get away without punishment. Damnit! What the hell was I thinking!" he mutters to himself as he cools off, putting away the blasters.
All of a sudden, he sees a flashing light in the distance near the ruins. Sans sprints towards it to see what is going on. Oh, fuck what if it's a human, he thinks as he walks towards the light. Then he stops. In the snow, where the light flashed, a skeleton laid face down. He wore what looked like children's pajamas. It appalled Sans. A red scarf was loosely around the skeleton's neck. Sans mistakes the skeleton for his brother, who looks just like him. Sans tries to lighten the mood. "What the hell is this Boss? You messing around in stupid children's clothes, what's up with that?" Red winced closing his only working eye, knowing his brother hates his comments. He waits for his brother to slap him, or yell at him, or worse. But a slap does not come. The skeleton figure rolls over seemingly in pain. Sans opens his eye and examines the skeleton more closely, immediately getting pissed off as he realizes this was not his brother in front of him.
Sans grabs the skeleton by the neck, pulling on his scarf tightly, almost choking the skeleton. "WHO THE FUCK ARE YOU JACKASS! YOU TRYING TO BE FUNNY OR SOMETHIN? IMPERSONATING THE COMMANDER OF THE ROYAL GUARD WILL GET YOU DEAD!" Sans yells, shaking the skeleton as he says this, furious. The skeleton slowly opening his eyes, barely conscious.
"and where the FUCK did you get this SCARF!" Sans loosens the grip on the skeleton, waiting for an answer.
"Whoa…h-hey yelling isn't nice…I'm the Great Papy-" Before Papyrus could finish he opens his eye sockets, focusing on the skeleton chocking him. Wow, his teeth are super sharp, and he is wearing all red and black, but he looks just like my brother, maybe he trying to spread a new fashion statement! Papyrus thinks to himself as he is being chocked. "S-sans?" Papyrus says to Sans, a bit confused.
"How the FUCK do you know my name?" Sans eye glows again, ready to summon gasters to destroy this idiot.
"W-what do you mean? We're brothers! I'm the Great Papyrus!" Papyrus smiles, sitting up as his strength regains.
"HAH, Yeah sure idiot, and I'm the commander of the royal guard! What the fuck are you smiling for?" Sans smirks then makes a frown, realizing this idiot is either messing with him or really is this stupid. Either way he is dead if he enters Snowdin.
"REALLY?! YOU'RE THE COMMANDER OF THE ROYAL GUARD!" Papyrus says excitedly. He stands up and hugs Sans tightly, lifting him in the air "OH MY GOODNESS I'M SO PROUD OF YOU!"
"H-HEY PUT ME THE FUCK DOWN!" Sans yells at Papyrus and struggles, Sans wiggles his arms and legs, trying to get out of his grip. Papyrus puts him back on the ground and looks at him with a confused face, "Don't you EVER do that to me again, what the HELL gave you the right to touch me! And I'm not the commander of the royal guard you IMBECILE my boss is" Sans responds furiously, his eye glowing red as he clenches his fists.
"I-I'm sorry…why are you being so mean to me…another Papyrus? What is going on…where is my Sans…" Papyrus sits on the ground, tears forming in his eye sockets, confused and scared. Sans stares at him in disbelief not knowing what to do, his eye socket turns to normal as he loosens his fists. Who the hell is this idiot, I wish I could believe he is just joking, but showing any kind of weakness like smiling and crying would've gotten him killed immediately, fuck this guy, Sans thinks to himself.
"Hey, don't start doing that stuff, it'll get you killed." Sans sits in the snow close to Papyrus, trying to reason with him. "If I could kill…I would've killed you where you stood" Papyrus responds to this by starting to actually cry.
"Y-you would, kill me?" Papyrus looks up at Sans, tears staining his boney face. Sans looks down, feeling regret for saying that.
"It's just how it is around here" Sans rests his head on his fist as he speaks, looking serious as he continues, "there isn't any crying, or smiling, or any of that shit, every monster just hates every other monster. It's always been like that here." Papyrus listened to every word, and then came up with the perfect solution.
"That sounds like an awful world to live in! BUT THAT'S OK! It just needs more friends and love, I'll be everyone's friend and give everyone spaghetti!" Papyrus smiles knowing his solution would be able to fix everything, he was sure of it. Papyrus gives Sans a congratulatory hug for coming up with the perfect plan, Sans lets him this time knowing that this guy is too far gone for him to understand the shit world he lives in. You know your brother is going to kill you if any of the royal guards sees you like this, Sans thinks to himself. Sans then pushes Papyrus off and stands up, taking Papyrus' hand and pulling him up to stand with him. For Sans, even if this guy is crazy, he has wanted a monster to look at him without feeling the need to fight or kill. He will not hand this fool into the hands of his brother, no matter the circumstance.
"I don't know where you come from ya weirdo but we can't stay here, if a guard sees us we're dead for sure and my shifts almost done with patrol. I'll question you more once we get somewhere safe I guess…" Sans says this as he starts walking through the woods, knowing that helping this idiot is a bad idea but feels responsible for him.
"Aww why can't I meet the other guards! I want to befriend everyone here! I am the Great Papyrus you know, I can do any-" Sans shuts Papyrus's mouth with what seemed to be a red tentacle coming from Sans back, made completely from magic.
"Will you shut up you idiot! Just stay behind me and don't say anything." He yells at Papyrus as he starts to walk in front of him, Papyrus defeatedly follows behind.