Unlike what everyone knew, Classic was never the original or the first Sans, not that anyone knew that.

That world and their resulting timelines were all gone, It's fragments and memories gone like dust in the wind.

It's data was used to create new timelines, starting with a new 'Classic Sans'.

But the Sans still existed... Kinda.

Let's just say that Fate... is very much a grade A bitch.

Destiny had great plans for the first Sans, plans destroyed by Fate urge to rewrite the worlds to her own whims and desires.

The first universe had to go, after all her future child's code wasn't compatible with it and that just wouldn't do.

She ripped Sans from his timeline, and threw them into there new home/prison the Anti-Void. They needed the Sans for later and his timeline as their starting foundation.

Once done ripping apart that, what she thought as, disgusting timeline she created her own and her sweet innocent child Ink.

Or rather she tried to, as she just couldn't seam to be able to keep him together.

But this was the reason they kept the Sans for.

Smirking they ripped out the codes from Sans, leaving the broken remains behind and left.

Their child was Perfect.

It was a surprise when they discovered Sans had survived, there form changing to a disgusting glitchy thing.

This could be useful.

There had to be a balancer so her Ink could keep creating, Ink would be so terribly upset if everything was destroyed due to there being no more room.

"Error, lets have some balance you disgusting piece of filth." Fate sneered with madness in their eyes.

And so the multiverse and time marched on, On the orders of Fate and amidst his insanity Error became known to the other judges as the merciless destroyer with an unrivalled thirst for dust and LV.

Until he accidentally kidnapped the Sans of Underswap No.0 now nicknamed Blue that is. Blue helped Error by...Friendshiping...his way back to sanity.

As Blue restored his world using Chara's soul, Error opened a Code Window to see if anything went wrong during the restoration and found something.

It was just a minuscule string of code, barely anything but it resonated with his own soul and code.

He found a piece of home.

Finding this, he started to look into other AU's and found more strings only in the originals of each AU.

So he hatched a plan, every time he went to destroy he would first check what AU it is then see what code resonated with him and then destroy the copy, but that string of code.

Which he then swapped round so he only has the code he wanted and that original AU would still be stable.

As Error slowly worked his way through the universe's, whilst keeping what he doing a secret from everyone and especially from Fate. He kept a large space cleared so when the time comes to restore what he believes to be his own AU.

It took him 8 eons to finally gather all but the Sans codes, after destroying a slightly higher number of AU's than needed he got to work.

Carefully piecing together the codes, double and triple checking to see if it was running as smoothly as they could. He stood in the Anti-void holding the ball of coding, he placed it in the cleared space and it came alive.

Opening a code window Error looked to see what's it's name was... Undertale. This confused him as there wasn't a number following the title, No.0's are originals and any higher are copies. The only answer would be that this AU existed even before Classic's timeline, which explains the title and the reson why the codes were so spread out from each other.

Opening a portal directly to Snowdin and he stepped through, crowds of panicking monsters became silent at the sight of him and then he saw a monster he would always have a connection with no matter how damaged or missing his own soul and coding was.

"Greetings" Error said his glitched voice echoing as he stared directly into another pair of startled sockets.

"BROTHER?" questioned Papyrus.