Ulty: the creation of a monster

The Fullfilled Vow

A: I am giving you a power beyond your knowledge, once you defeat the human you have to find a way to bring them back to life, you have to promise me!

D: He ... hehe ... HAHAHA!  Should I bring them back to life?  How do you think ... is ... possible? .....

Dust had an idea

D: If the human is able to reset ... with this power I can steal his powers, kill him and bring everyone back to life!

A: So, is that a promise?

D: Yes Asgore, I promise we will all have the ending we deserve!

.....

Snowdin was a happy city, unaware of what had happened.  Ulty found himself in his room, he had managed to fullfill his vow with Asgore!  He looked in the mirror and noticed that it was a material skeleton and was no longer a cloud of smoke.  However, he was taller and more muscular than a normal sans, he tryed to use his powers and surprisingly it worked.

U: Haven't ... haven't I lost my powers?

Ulty transformed back into his gaseous form with his old battle clothes and looked in the mirror again.  Eventually he returned to his skeletal form but kept his battle clothes.

U: This is Ulty!

He transformed back to his Classic Sans form, put on his clothes and left the room.  He went down the stairs and in the kitchen he found Papyrus cooking his almost edible spaghetti.  Ulty hoped to experience something special seeing his brother but his journey had changed him radically, he was no longer what it used to be ...

He went back to the room, reasoned about what to do even though he already knew what he had to do.  After a few minutes he decided to do what had to be done: he evoked a copy of himself Classic version, he created a code identical to that of a Classic sans in order to make everything seem normal to his brother.

He said goodbye for the last time to the life he had hoped to return to and teleported to his old base in the Outertale asteroid, only his base wasn't inside it.

U: Right ...

Ulty decided to proceed differently this time.  He opened an interdimensional portal that allowed access to a dimension that only he had access to.  This dimension was completely empty, vaulted like the antivoid.

Ulty began to build his new base, initially aimed at a military style like that of his old base, then completely changed his mind and created a mansion.  He opened various portals for all known Aus, sat down in his new living room looking at a huge scale with a black plate and a white plate hanging on the wall.

U: And this... is where my new life begins!