Sans figured the nightmares were coming from somewhere. "It has to be coming from somewhere, doesn't it?"
To Sans' astonishment, his room got dark and many blue doors surrounded the room, "You wish to know, pass the test." A voice came in Sans head causing his eyes to blacken in surprise. "What are you?"
Sans was glad he spent all that time mastering his poker face. Too bad the involuntary eye issue couldn't be fixed. Who knows if this thing can see.
"Relax, Sans, I'm part of the universe. Spiraling Stars is what I am." Sans couldn't help it, he uncharacteristically stepped back in surprise. He read about this, they control the universe, which is activated through Origin's Gate.
"Why are you offering me a test?" Sans wasn't going into a pop quiz that could kill him without some answers first. "Someone must keep the secrets of the universe and you are worthy, Sans."
Despite his gut screaming at him not to, Sans brain told him to agree, and he walked towards the blue door. "Well done, test subject." "What?" There goes his eyes again.
Sans found himself in a room that was too hot, even for a skeleton like himself, along with being suspended at what he thought was 100 feet in the air, he could see some platforms if he looked down.
But he figured that would be hard to make, as metal was smashing together under him, in multiple places, and if the sound was grating now, how hard on the ears would it be up close? "Get a good look, test subject?" "Uhh, can I go back?"
Sans being flipped upside down told him the answer was no. He would normally fight back, but how do you win against an invisible opponent who controls the universe? "Now, pay attention. Here you are not considered a person or even a thing, got it." Sans nodded. "An it doesn't get a choice in anything, which is why here, I control your magic. Can you guess where I'm going?" "I'm not allowed magic." "Now, let's move on."
Sans was dropped, going flying through the air. Okay, don't panic, Sans. "YOU DON'T HAVE A NAME HERE!" That thing could read minds too? Never mind that, think.
Sans saw the next platform was ten feet down, he must slow himself. He was already wearing loose clothes, well his slippers may have been too loose as they went flying, sometime during this unwanted freefall.
He laid flat, arms stretched out, along with his legs, please soften the blow. He knew he shouldn't have came, but did it anyway. He finally landed, on hard cold metal, he must have broken a few bones, judging by the cracks. "Here, broken bones are just an inconvenience, for it." Sans was pushed off the edge by an invisible force, crushers sped towards him.
Sans grabbed the arm of the crusher without thinking, he may die here, his brother looking for him in a search party of some sort. "Papyrus would be relieved without an it around." Sans kept his poker face, against a mind reading opponent, as he flipped himself to the next platform.
Knowing he would just be pushed down, if he dared to delay his hell, he jumped and timed the fire, when the flames went from sideways to upwards, "Let's see if it can handle a harder challenge." Fire also came from the top, shooting in and out.
Sans saw water on the metal crusher he just got past. He had no choice, he placed his hand on the crusher, grabbing the bucket of water and poured it on what he thought was the source of the flames.
He must have passed whatever cruel test he was subjected to, because he was thrown towards the door, crashing into a wall, in his familiar room. At least his brother wasn't home. "Well done, Sans. You are determined enough to learn the truth."
Sans then saw everything, everything that happened. He couldn't make progress, every time he did, the world reset. "I don't want it!" Sans exclaimed when he now knew where the nightmares were coming from. "Sans, one can't take back what they have given. Your request must be unfulfilled, I refuse to grant you your request."
In an instant, the blue doors disappeared and it was like Sans never took the test in the first place, if it wasn't for the unwanted memories left behind.