This idea was hilarious and even tho I don't know shit about Palette except his heritage I'm gonna write crack. Another prompt from Fire, btw.

Once upon a time, Ink and Dream had a kid.

Except actually, they had twins, and it was Dream's fault. Something about him and Nightmare and the tree.

Nobody really cared that much.

Well, Ink kinda did.

Ink, being Ink, decided to assume the kid's future roles in the multiverse.

He assumed that since Nightmare was evil one of the kids would end up going 'dark' too.

He assumed it was the kid they were going to name Roller.

So Ink, being a total fucking moron, yeeted Roller into the void and told Dream Roller died.

Dream believed him. This was one of two very stupid choices Dream had made in the past year. The other being having any kids with this spastic soulless numbskull.

The other kid, Palette, got his brother's names tacked on, so now he's Palette Roller. Makes total sense, right?

Maybe it does; I don't know. I've never named a kid before. If it was up to me, they'd be Mario and Luigi or something. Probably why I'll never have kids.

Anyway, so Roller's mostly dead in the void. He's like five minutes old, no idea what's going on, barely even aware that he's alive.

Then another fucking moron decided to mess with the poor kid, because he hadn't been through enough in his ten-minute life.

Fate decided to pick him up and plop him in the past, years and years before he was born.

She had kinda needed a destroyer anyway; now she doesn't have to wipe anyone's memories! Thank herself for Ink's impulsive stupidity!

So she 'raised' the kid (read: she dropped baby bottles in the anti-void but that was about it) and named him Error, and made him destroy AUs. Because balance or some shit.

During his time in the Anti-Void, Error became very glitchy. His bones changed color, he's now covered in 'error' signs.

Fate's just so creative with names. Maybe she's related to the original Asgore.

Eventually Error met Ink, who was going to be his dad, but this was before Ink even met Dream, and Error had no memories of his parents except for a vague memory of a song. Probably Dream singing lullabies to him and Palette when he was pregnant with them. Again though, how the hell was Error supposed to know?

Many years later Dream decides being a statue sucked ass and escaped. Around this time Error was pissed at Ink and beat the mcshit out of him.

Ink, who had absolutely brought that upon himself, was feeling sorry for himself, which attracted Dream because he like em sad.

No actually Dream is just a nice guy. Why he decided to do the dirty with Ink, the world will never know.

Ps Drink is actually cute and Ink is awesome but I'm having too much fun beating down on this specific Moron Ink to care sue me lol

A few more years later and Roller and Palette are born again, only this time Roller aka Error exists so when Ink chuckles Roller into the void a paradox that we're not even going to think about happens. We're just going to not think about how that works. There was no Error, then there was an Error. What happened to 'new' Roller? Is he just chilling in the void now? Did the Gasters raise him? Was Fate like 'welp might as well keep the chain goin' and create a new Error?

Fucking butterflies, man.

Ignoring that, Dream, who has no idea that Error was the kid that 'died,' begins to raise Palette with lots of love and attention.

Meanwhile Ink tries to be a good father despite being an ADHD goldfish who is basically a drug addict only his drugs are paint and is already a terrible father for yeetus deletus-ing Roller.

But wait, there's more.

Fate, in an attempt to break Error's spirit, told him that his dad tried to kill him as a baby.

Something about being unwanted yada yada yada.

Ink happened to decided that the best place to yeet a child into the void was Outertale, which was a place Error really liked. Probably because it reminded him of his birth.

Isn't it calming to be reminded of how your loving father threw you off a cliff into the great beyond when you were five minutes old?

Yeah.

Error saw this.

But Error, thank Luck, did not inherit Ink's stupidity.

But, unfortunately, he didn't know that Fate put him in the past, and didn't make the connection. He was just kind of unnerved.

Finally, Karma, being the cheeky little bitch she was, decided to cause trouble. This was several years after Palette and Roller were born, so Palette's like. Ten, twelve years old?

Karma is friends with Error. And by friends I mean she occasionally messes with him but mostly helps him steal chocolate.

Due to her association with Error, Nightmare and his gang know her too.

And Ink knows of her existence; probably seen her once or twice.

Dream knows she exists but that's about it.

So when she decides, in the middle of a battle between Ink, Dream and Blue and Nightmare's gang and Error, to freeze them all and announce that Error was the kid Ink tossed off a cliff, everyone knew who she was and that she was a reliable source.

Error crashed. Several times. In a row.

Nightmare's gang wasn't sure whether they should be angry or amused.

Nightmare was unsure how to feel about Error being his nephew.

Ink looked like a deer in headlights.

And Dream...

Dream was fucking pissed.

When Error rebooted and didn't immediately crash, Nightmare, being Nightmare, said, "Sooo. Error. Yknow how you say I'm not your dad."

"5hu7 7h3 fuck up!" Error screeched.

"Is that any way to talk to your uncle?"

Error, who was having an existential crisis, crashed again.

"Ink."

Ink finally realized he'd fucked up.

Dream had murder in his eyes, and when Dream was that pissed, nobody got away unscathed.

Several multiversal lawsuits later, Ink was forcefully separated from Broomie and all of his art supplies, and Dream had invited Error over to meet his twin brother.

"Daddy told me you're my twin brother and you went back in time," Palette said excitedly, "is it true?"

"1...7h1nk?" Error said, scratching his skull. Honestly, he wasn't sure how he felt about it.

Palette, looked awed. "That's. So. COOL!!"

And so Error had to suffer through his little twin brother's fanboying.

Error's job as destroyer was mentioned once, but Palette just thought that was really cool.

Error could see his Palette was Ink's kid.

He did not understand how he himself was.

Now, with all this hubbub, everyone was wondering how the actual fuck Error survived being thrown in the damn void.

Pretty damn impressive.

Eventually it was found out that Error and Palette each had half a soul.

Wait, does that make them soulmates?

Well, it doesn't really matter, because that's how it is.

Familial soulmates? Sure, why not.

Error is questioning his existence again.

Palette wants to be like his big twin bro.

Years pass.

Ink is allowed to art again but Dream isn't going to forgive him for yeeting Roller into the void; understandably.

Nightmare realizes that he's so affectionate with Error, even before he knew that he was his nephew, because soul logic and family and some sentimental bullshit. He didn't care though because he was having fun being that uncle who was always pulling pranks on you but would also kick ass if someone hurt you.

Nightmare would be a good father one day.

As Palette grew up, he continued idolizing Error. Because Error was awesome.

Error got used to having a brother, and Palette and Dream actually started to to feel like his family, and it was kinda cool if really fricken weird.

Then.

Nightmare.

After figuring out why Ink yeeted Error off a cliff and into the void, decided to be a huge fucking troll.

Because he's Nightmare.

He snuck up to Palette, who was now about 18-20 and was actually a lot like Ink but without most of Ink's problems (memory loss, being emotionless, compulsive urges to through babies into the void, etc), and said, "Hey. Come to the dark side. We have cookies."

Palette gesped in delight and immediately said yes.

Because everyone loves cookies.

Nightmare, being a good uncle and not really intending to convert Palette to the Darth Side, just had him throw paper balls at people with messages like 'Noot b comin 4 u' and 'all da cookiez b mine'.

Palette, not being an idiot, knew that this wasn't really evil, but he was getting cookies so he didn't really care.

Nightmare eventually promoted him to genuinely threatening messages (such as 'Ima steak ur cookies hoe')

Error, who had been wondering where his little twin went, visited Uncle Night to ask if he knew.

There he found Palette waist-deep in cookies and getting diabetes.

"Br0," Error said, "wh47 7h3 fuck."

"Cookies!" Palette giggled, on a scary sugar high.

"Cookies," Nightmare agreed.

"...P4l3773," Error sighed, "Dr-uh...d4d-" it was still weird calling Dream that, "-w45 w0rr13d 4b0u7 y0u, 4nd n0w y0u'r3 h3r3 3471n9 c00k135?"

"Yep!"

Palette was a simple man.

To be fair, Error would do a lot for a lifetime's supply of chocolate, so he couldn't be too mad.