Undertale Universe, Papyrus and Sans's house.
"This must be it after a few years have passed I've finally found it" Breach walks closed to the door and knock it.
KNOCK KNOCK.
"YES, HELLO ANYBODY THERE" a voice speaks as it walks towards the door and opens.
"HUH, WHAT THE HUH!" it reveals a tall skeleton with small eyes.
"WOWIE YOU'RE A SKELETON" shouted the tall skeleton.
"Who are you?" said Breach.
"OH OF COURSE MY NAME IS PAPYRUS AND I LIVED HERE WITH MY BROTHER AS SANS" said Papyrus.
"Oh, okay so Papyrus may I speak to my father" said Breach.
"HUH, FATHER?" said Papyrus.
"You see here" Breach explains everything.
"That's how" said Breach.
Papyrus has a lightning bolt struck into his head and heart as he ran into Sans's room and shouted.
"SAAAAAAAAAAAANS, YOU WON'T BELIEVE WHAT DID I JUST HEARD" shouted Papyrus.
"What is it Paps, something wrong" said Sans.
"THERE'S A SKELETON WHO CLAIMS TO BE YOUR SON" said Papyrus.
"GUH" Sans walks outside.
"So, your my son how should I believed that" said Sans as he grins.
"Do you remember the time you've met a woman in the afterlife that said she's going on vacation on the underground and she helped you fight against the evil human" said Breach.
"Huh, yes exactly although it is strange how could you knew about it I mean I never saw a skeleton like you before" said Sans.
"Right, you see here the woman you've met and helped you fight the evil human was named Yukari she's a humanoid Youkai that is the last of her kind a unique type that alters boundaries" said Breach.
"Uh huh (He gets it all corrected and know allot about Yuk)" Sans just wait for another answer.
"During the time when you and her are fighting the human the youkai as Yukari accidentally transfer a part of her powers into your soul and it separated into a new soul due to the point because you couldn't handle allot powers that aren't allowed for monster after when you were been dusted into the after life and the human reset, I've did a few discoveries about the existences of the outside of outside universe and learned allot of things after I finally figure it out that you're a skeleton that was been created in the lab by a man named W.D Gaster along with uncle Papyrus I knew that I'm more like a entity a hybrid entity more than a skeleton.
"You…you…you got it all correct you even know who we were from our past self" said Sans.
"Yes now that you believed me I must speak to you something" said Breach.
After a while.
"SO LET ME GET THIS STRAIGHT THE FIRST FALLEN HUMAN HAS BECAME EVIL AND TRIED TO MANIPULATED THE HEART OF OUR FRIEND, FRISK THE HUMAN THEY ALL ATTEMPED TO MASSACRE ALL OF THE UNDERGROUND AND IT WAS A SUCCESS I, UNDYNE, METTATON, ALPHYS ALL END UP BEING DUST AS FOR YOU, YOU WERE BEEN REBORN FROM THE AFTERLIFE ALL THANKS TO A WOMAN WHO TURNS OUT TO BE A HUMANOID YOUKAI SHE GAVE YOU A SPECIAL POWER BUT THEN ALL HER PROGRESS AND YOURS ALL TURNED SUCCESS AND A BIT USELESS SINCE IT DOESN'T MEAN THE HUMAN DIED, SHE TRANSFER A PART OF HER ENERGY TO MAKE YOU RECOVER ALL YOUR STAMINA BUT SOMEHOW THE ENERGY WAS TO OVERPOWEPRED SO A TINY BITTY PART OF YOUR SOUL WAS BEEN SEPARTED AWAY FROM YOUR BODY AND FINALLY IT FORMED INTO BREACH ALSO KNOWN AS YOUR SON" said Papyrus.
"Exactly Papyrus" said Sans.
"HOLY SHIT ARE YOU KIDDING ME" shouted Undyne as she appears out of nowhere.
"GAH, HOW LONG HAVE YOU BEEN HERE" shouted Sans.
"We've been here for as long as the conversation I can't believe it…you…you…have a s…son" said Alphys.
"I'm really shocked about that" said Toriel.
"Indeed, it's kind a shock" said Asgore.
"GAH TORIEL, ASGORE" shouted Sans.
"Heya we all heard it too" said Frisk.
"Listen I'll be taken this boy to his mom now" said Sans.
"Hmmmm" Breach checks Sans's soul.
Name: Sans ?ATK, ?DF
Race: Monster/skeleton
Age: 25
Occupation: Judgement of the royals (Retired due to the point because the monsters are all set free), grocery manager (current job).
Soul: Monster Soul/OVERPOWERED SOUL
Description: Yukari gave him the overpowered soul when he was battling with Asriel…
"Hummmm welp dad I'll be with you now" said Breach.
As he walks thru the portal with Sans as it closed.