Reverse the Reverse Potion (Fgod Error)

Prologue: The Start.

    ..This isn't like any other Fgod story.

It all started eons ago, a deity, named Fate created their multiverse.

Oh, their multiverse was the best, it had only a few universes and especially, the original au, called Undertale.

The few others were Underfell, Underswap and Outertale.

The AU Dreamtale, popped out of nowhere but was a young universe that doesn't have the skill to AU jump just yet.

How sad, Fate doesn't get a chance to meet them yet.

But slowly, Fate began to lose their hold on their multiverse, and to maintain it, they made a creator and a destroyer.

The creator, called Ink, loved to do their job. They would spend time doing their job with passion.

(Yes, Ink has a soul. But due to Fate rushing, there might be a problem when it comes to emotions and memory. So, Fate gave Ink paints and his scarfs to write on instead.)

On the other hand, the destroyer, named Error, was stubborn.

All he wanted to do was nothing.

In order to make Error destroy worlds to keep the balance, Fate made voices.

So when the balance was almost tipping, those voices will remind Error to destroy whether he liked it or not.

But the voices Fate made weren't that mean, they are just like those annoying alarm clocks that ring when you have to wake up for school.

Soon, Fate, without any hold on her multiverse anymore, left and never came back.

Time passed and Fate was almost forgotten by many.

Reset-affected universes, which were the ones whom Fate met before, sadly forgotten Fate as well.

Fate thought that their multiverse would be fine.

But things.. got out of hand..

Ink loved creating.. Maybe a little too much and thus, he slowly began to overcrowd the multiverse.

Meanwhile, Error destroyed without Ink noticing, as the voices were annoying.

But nothing can be kept hidden forever.

Ink caught Error destroying one of his worlds, he became angry. He failed to try to see the other side of the story and assumed everything about Error.

..Can't blame him, he has a defective soul.

Words spread like wildfire, and there were rumors about the ruthless destroyer.

Error doesn't even know that this is happening.

I mean, what do you expect? He doesn't have friends. Yet.

Anyways, a few au resets later, the kidnapping accident happened.

Blue, being a smart monster that didn't believe in those lies, tried to befriend Error.

Yay. Error finally has a friend now.

A few more au resets later, the apple incident happened.

Nightmare, confused, scared, and alone, was found by Error and Blue while au hopping.

With the annoyance of Blue, Error, somehow still stubborn, agreed to help Nightmare.

And with a bit of code and "borrowing stuff", Error got Nightmare a castle, which Error added a little room for himself to avoid the annoying voices of course. 

*he totally doesn't have house privilege now*

Blue, who taught Nightmare how to make portals just then, knowing Error's intention of making Nightmare a castle, facepalmed at Error.

Meanwhile, Dream was freed from stone. Ink helped him and as clueless as Dream is, he believed all those rumors and lies quickly.

Blue noticed this and took action by joining their group, the Star Sanses, hoping that he'll make Dream and the others see the truth.

Soon, the 'Bad Sanses' was established, well at least that is what Ink called Nightmare and Error.

Dust, Killer, Horror, and Cross soon entered the group.

Let's just say that Nightmare's motherly instincts were activated the moment he laid his eyes on them.