The day of first...

                                    

                                          
Error had enough. Ink never listened, he had met an interesting being named nightmare who had tried to talk him into not doing what he was thinking of doing...
Error had enough. 
They didn't want him; Fine.
At least Gaster was better company! 
They wanted him to disappear then mote it be.
And that was how Error left... a young multiverse, barely a thousand years old, to sort it's own shimmy out without him.
...
The deities were not amused. How had such a young multiverse failed so miserably? It was sheer luck it was young enough to still adapt... they needed only a little push. 
The stone of a guardian, a world so damaged the antivoid would easily consume it, and a single golden apple.... the sky cracked from blood red to white, an all consuming brightness. 
....when the tree and sky became nothing but that same brightness, all consumed... the statue split and out fell the Positive guardian.
"Where am I?" He asked glancing over the nothingness surrounding him. Looking around he found only one thing... the golden apple. The thing that started it all.
"Mama.. why did you create us..?" He asked mournfully as he gently picked up the fruit. He sat with it in the endless white not knowing what to do or where to go.
Crying. 
While he and his brother had been 25, they aged very slowly, so physically he was only 8. He missed his brother, he missed the tree, he missed the quiet whispers of the wind... 
But somehow he knew... those times were gone for good. 
Standing shakily from sitting and crying, The skeleton guardian stood. "I am Dream, guardian of positivity, I can't afford to fall into despair...! That's right. I need to find a way out!" He resolved for himself. 
And so he marched into the endless white. 
Time in the antivoid was weird... especially when one was moving. The more they moved, the less time outside would pass, yet somehow more time relative passed all together. 
Dream had no way of knowing how much time had passed. It could have been hours... it could have been days... but he knew at least for himself it had been far longer then that by the time his spirit started to hurt badly from the lack of consumable energy...
He gazed at the apple in his hands... he was so hungry... and surely Nightmare would eat it too if he found it while he was so weak...
Reasoning with himself didn't stop the guilt as he ate the slightly glitching golden fruit. Core, seeds and all. Magic tears trailed down his face, soft sobs escaping him.
Yet, with resolute determination, he squashed his fears, his grief and his aching loneliness to stand tall, he yelled into the antivoid, demanding. "I CAN FEEL YOUR EMOTIONS! COME OUT! PLEASE, I WILL NOT HURT YOU, HOWEVER DO YOU NOT THINK YOUR PRANK HAS GONE ON LONG ENOUGH?" he called...
Yet no one came.
Dream ran in the direction the strongest emotions came from.... there was nothing. The emotions faded away and appeared elsewhere. So Dream kept chasing them.
Days? Months? Years perhaps??? Dream didn't know. 
He collapsed onto his knees and started screaming, he didn't have lungs, he didn't need to breathe in or out and so his screaming was continuous...
Anything to fill the unbearable silence. 
He didn't know how long he was screaming. 
It could have been years... it felt like decades. 
And then.... the screams came back.
Yet even as he stopped screaming...
No one came.
When the screaming stopped, he started talking to himself, Anything to keep his sanity... Anything to keep him going. 
And yet... he could feel himself loosing more, and more of himself as time went by. His bones were glitching into different colours, his clothing torn, his boots he had taken off briefly had glitched out of existence....
Dream decided to keep himself busy learning magic. 
And so he spent a long, long, painfully long ungodly amount of time learning his magic....
Before he finally broke down. He stopped talking. He stopped moving. He just cried for a very long time in that white hell.
And that was when he felt it. He had by this point forgotten his name.... but he knew what he must do. He felt a pull of Positive emotions... and followed it, he managed to create a one way window using the glitchy magic! At last he had something other then the white hell!
And so he watched. It was a child, a human child. They had freed all the monsters from an ancient imprisonment. 
The colourful skeleton was intrigued and wanted to know how they had done it... and so it was that he learned his next abilities... he could see the code of that world, had "seen" the many possible routes... and learned how to rewind the viewing for such events. 
He watched it all. And yet, the more windows and code he looked at the more excited and concerned he became... according to the code...
The multiverse had a limit. It was very close to said limit if the numbers were to be believed...
Looking at his own code. He found he had an ability due to code access called erase... he looked towards the screens again. He knew these monsters. They didn't know him, but he knew them. He didn't want them to die or fall into the void to suffer never knowing why...
He became determined to leave this place... determined to save them all. Even if they didn't realise it, even when they would come to hate him for it... he refused to allow true despair to claim any of their souls. As he gazed back to the screens. 
He swore to be their guardian of destruction. The guardian of their dreams; their future. He clenched his gloved hands, he could do this!
It was then, for the first time, through sheer determination and force of will, that the Guardian tore open reality, not in a window, but a portal, to a genocide timeline AU to start his job at last.