A beginning of a destroyer that denies death

== Back story: a universe with the most Fatalities ==
after the Event of Origins ,sans,frisk and the rest of the monster left the underground and go to the surface with a flower 
after 5 months of peace.
Sans brother papyrus notice something from his brother sans he became less lazy & started killing some animals & insect. 
so the last fallen human. Frisk goes to visit Sans than brings him outside & ask him what going on with him sans said ‘well kiddo the soul I absorb has give me one problem it kept giving me an urge to kill so thank to that I now have Lv 20 now’ frisk gasp in shock than was about to reset sans stop them & said ‘woah bud that not a good idea & beside this soul can resist reset’ frisk became worried sans said ‘heh don’t worry I could control the urge anyway I gtg’ sans has teleport to his house. Frisk was concerned at first but decided trust sans than they left 
meanwhile in sans room. Sans is having a conversation his ghost buddy Hank. 
Sans ask ‘well since we don’t have to deal with more reset it time to ask ya something what kind of soul is this 
Hank reply ‘fatality soul this soul is so powerful that it transcend the capabilities of determination & transcend death itself but how I got it……..Well my dad and my cousin dad did an experiment on their soul’ 
sans reply back ‘ah I se- wait you have a cousin!?’ 
Hank said ‘yea but he gone’ 
Sans said ‘oh I’m sorry that happened to him but what happens to you. Where did you come from‘ Hank replied ‘well my body has been killed before the war’ sans was shock than said ‘wait before the war you mean the war of humans & monsters that happened many years ago who even killed you’ 
Hank had remembered something terrible. His face sadden than said ‘you see every human in my village was attack by a monster but that monster wasn’t an ordinary one…..it’s was unstoppable…well almost. Me & My cousin together stop him..but we didn’t won the battle. He used an insanely powerful special attack against us and after that I sorta died, my cousin was lost & that powerful monster disappeared’ 
‘who was that monster & how is he so powerful’ sans ask. 
Hank responded ‘for the latter I don’t know how or why….but I feel a weird energy from his soul & for his name I barely remember..I think his name is mi-‘ then they hear an explosion sans shrug until papyrus kick down the door then said ‘Nyeh?! Sans? If you’re here than who is that attacking the city’
sans was confused & said ‘huh what are you talking abo- until they hear another explosion sans teleports him and papyrus to the city they see a lot of buildings destroyed 
‘Paps was is going on?! Who is doing this!?’ sans ask 
Papyrus answered ‘I saw a news report of you attacking everyone’ 
sans said “what?! But I would never-‘ 
‘he right. HE would never. Well not this version’ said a ominous figure 
sans became shocked. He saw an evil doppelgänger of him with red eyes & in different clothing. The one responsible of destroying buildings. Not only that he feels a chaotic energy inside of him 
sans ask ‘who are you!’ 
The other sans said ‘Hehe…..HAHAHAHA..heh I am you well to put simple an alternate version of you, shocking right? It’s like looking at a mirror & to avoid confusion I am horrible sans I came to destroy this world. My master send his regards’ 
sans blast horrible & said ‘papyrus run away & get the people out of here’ 
papyrus said ‘b-but sans what about yo-‘
‘I said go!’ Sans said 
than horrible punch sans so hard that he went flying than crashed into a car next to frisk who has help him up & toriel heal sans & ask ‘sans what going on’ sans replied ‘I don’t know’
toriel was finished heal him until toriel was pierce through by horrible axe frisk scream mom. ‘M-my child’ toriel said before getting her head slice off by horrible sans cleaver than horrible sans rip toriel face into 2. Toriel body turn to dust while horrible sans just walks on it. 
Then he said “sorry kid but master order” while giving frisk a death stare
frisk was about to press the reset button until horrible stab them with his axe than use it to destroy the reset horrible was about to grab their determination soul sans use blue magic to grab frisk body 30 feet away from horrible
horrible sans ‘I guess Mike was right Hank is a shithead’ 
sans ask ‘wait who is Mike-‘ but he was interrupted 
‘that doesn’t matter now you die fatality sans’ 
sans ask ‘did you just give me a nick nam-‘ 
horrible use his gaster blaster to blast fatality sans but he doge it & the blast end up hitting a building than creates a huge explosion. Destroying 1 skyscraper & 10 buildings 
fatality said ‘kiddo I need you to reset-
‘it no use I have destroy their reset button’ said horrible. 
Fatality sans sweats & said ‘well crap I guess I have no choice i must make this sacrifice’ sans absorb frisk soul the power boost he got was incredible 
”wow that’s cool I’m at least twice as strong as what I was before. Now horrible give me some answers or have the biggest bad time you will get. You choose” said Fatality sans 
Horrible just said “you are the one who gets the biggest bad time! So you want answers? Come and get it” 
than fought horrible the battle was intense fatality sans was dodging every attack from horrible while horrible just fire a barrage of bones than he lift a building than throw it at fatality just simply teleport behind horrible than kick him into a building than just use 5 gaster blasters on him 
The building blows up than horrible dash towards fatality with an Axe. fatality block it with a bone than both of them clash their weapons together multiple Times than fatality use blue magic on horrible to throw him to the ground than teleport in front than punch him so hard that he went fly to a building but fatality wasn’t done yet he use blue bones on horrible & use his gaster destroyer on him the explosion was big that it damaging horrible pretty badly not only that there a big hole in the ground than horrible jump out than landed. He was in pain because that attack even break horrible sans top part of his skull 
fatality sans said “heh done yet? Or you want some more. Just tell me. Why are you doing this. Why are you bad to the bone. You’re an alternative version of me right? What’s making you do this. Who. Is. Mike?” 
Horrible sans was enraged. His eye glows red then said “I’m. Not. Done yet!” 
he screamed than use 100% of his power. he blitz in front of Fatality sans than donut him aka punching through his chest than throw him on the ground than finished him with his axe before horrible axe land fatality error just disappeared. The axe slam on the ground creating an country size earthquake 
“W-…..WHAT. Where did he go….ugh my head hurts…..I’m losing control of myself. Rrrrrrraaaaaaaaaaaaggggggggh” horrible sans screams than go’s on a rampage 
meanwhile 
Fatality sans didn’t die in fact. He was able to teleport to what appears to be a white void he look up than saw a lot blue & red string up there he tried to go back but he can’t. After a few minutes he was worried what horrible sans is doing. Suddenly 
The string grab fatality sans hand he said ‘what the- why can’t I use magic….hey stop that strings!’ 
He begin to glitch than said ‘let go of me string’ he keeps glitching until he screams ‘STOP!’ A huge glitch aura appears than exploded 
fatality sans woke up but he feels different than he noticed something & and said ‘am I taller now?- wait why do I feel weird, what happened to my clothes,wait are there strings in my eyes and is that a scarf!? I feel like an error happened here’ he look at the strings & said ‘well I am staying away from you for now’ than teleports
After he teleports to his world. He saw the whole city being destroyed he look around trying to find some survivors all can he see are blood & dust 
he walk around for long time while hoping nothing bad happens to his brother due to knowing that there will be no resets
until he heard something than he found his brother papyrus who was walking around calling for some survivors
papyrus was surprised when he saw sans. Due to sans new appearance it took paps a while to recognise him so papyrus Said “nyeh!! Who are yo- wait sans! Is that you?” 
sans replies “yep I seem to gotten makeover anyways what happened here” 
papyrus response “your weird doppelgänger killed almost everyone here & was destroying the city but for some reason he didn’t try to hurt me maybe because I’m so great also is the human alright” 
sans said “frisk is fine I just absorb their soul but even with that I couldn’t stop him but this might sound weirdly unbelievable for you. I accidentally teleport to a weird place & there are strings that turn me into this” 
papyrus said  “ wow weird place? What are you talking about? Wdym strings that turn you into thi- wait you look taller dose that’s weird place give people grow spurt? How-actually never mind Look you can tell me about that later I think the doppelgänger of you has left” 
sans said “oh that good but what are we gonna do now that other me has killed skeleTONS it would take us all day to find survivors till we’re bone dried I was lucky to find you” 
papyrus said “sans enough of the puns ((why do you keep making puns on serious situations like this? ) he thought) I able to save some people after the attack I’m still looking for more” 
sans said “wow paps your so cool that you can find people so fast” 
papyrus said “I’m fast but not that fast it took a few hours to find some survivor’s- 
sans interrupt “wait few hours!? For me it felt like a few minutes in that weird place. What going on”
papyrus said “again you can tell me about that later. just what are we gonna do when your doppelgänger might come back? He destroyed almost everything ”
sans ask “is there any of our friends alive?”
papyrus answered “well I know that undyne. Alphys. Grillby and a guy name Jerry is alive but asgore & his lady version has been-“
sans became a bit sad than finish paps sentence “killed”
papyrus was saddened than replied “well yeah that. I can’t believe this happened. Why did your doppelgänger do this?”
sans answered “well he did say something about his master maybe he was ordered by this…..Mike” 
papyrus was shock than said “Mike?! So you heard that name too. When I tried to help That doppelgänger sans he said “sorry paps my master. Mike gave me order I hope you live after I mess up this world” so that doppelgänger must be working with Mike”
sans said “let talk about this later there are survivors. & like you said he might come back….soooo we might need to use a new place for shelter”
papyrus said “ ! Sans your a genius we could use that weird place for our newer home” 
sans said “I don’t know if that a good idea I was trap in there when I first came 
papyrus said “but you manage to escape so come help me find more survivors & start working on a newer home” 
sans said “sure bro…i hope those strings don’t do anything harsh” than they start looking for survivors they managed to find some but most they could see is blood & dust everywhere
5 hours later
papyrus & sans Found undyne out of the city. Undyne was suprised by sans new appearance 
”wha- sans! Is that you!? I thought you died and. You look different?” Undyne said
papyrus said “well it’s a long story but we managed to find some survivors in the city”
undyne said “well now what?”
sans said “I found a void that I accidentally came through & paps thought we could use that as our new home”
undyne said “is it safe?”
sans said “beside the weird stuff it did to me. In fact I was fine in there”
alphys said “o-ok the a-amount of s-survivors we g-got is 200 human & 210 monster excluding the f-four of us”
“well only 200 human & 210 + 4 monster has survived…not good but not bad either” papyrus said 
“Welp time for our newer home” sans said 
“Wait I’m not done yet” papyrus said while he finished creating a gravestone that the same size as a house with a sign that says “here lies our family & friends in our destroyed home
After that sans chuckles teleport himself along with papyrus, undyne & alphys & 410 beings into the fatality void
the story continues in Fatalitytale Chapter 1 : newer home with newer friends