I got this idea yesterday and haven't been able to share it. It's basically a Fgod!Error idea.

First, a headcanon that I thought of: the ones that monitor their side of the balance(Dream - Nightmare, Reaper - Life!Toriel, Error - Ink(though maybe he can't tell due to lack of a Soul)) are able to tell when the balance is off to some extent. Like, Nightmare can tell if there's too much positivity, Dream can tell if there's too much negativity, etc. And can, to some degree, tell when other parts of the balance are out of balance. Which leads to this idea:

In this idea, Dream is questioning the motives of why Error destroys AUs. He's unable to get any answers from Error himself due to being busy trying to help the citizens of any AU that Error's destroying while Ink fights him. And Ink doesn't help much in finding out why because he's either busy making AUs or busy fighting Error. And Ink had tried asking Error before but got no real answer, so he gave up asking that way. Dream can tell there's something wrong, but he can't pinpoint what the cause is.

Skip forward to after Error decides to jump into the Void, and the multiverse is on the brink of collapsing itself. Fate, being angry about Error escaping her and being frustrated with Dream, who is still questioning why Error was destroying and the bad feeling he's had has only gotten worse, decides to punish Dream by choosing him to fill in Error's role.

Dream is physically and painfully changed. He was alone in his ruined AU when he felt this tremendous pain in his chest that spread to his whole body. Nightmare feels something wrong, and after trying to pinpoint where this feeling of wrongness was, he goes to check, only to find Dream, although almost unrecognizable now. Dream is still in immense pain when Nightmare finds him, and Nightmare is horrified by what happened to him. He was still upset over Error leaving(or possibly believes dead), and now his brother was forced into the role Error hated. But he also knew that the multiverse was hanging on by a thread, and while he was doing his best to corrupt AUs, it wasn't enough. Still, he wished it was anyone else except his brother. He stopped truly hating him a long time ago, having the gang around had helped him come to terms with what happened in the past. He never bothered to tell Dream before, though, too busy helping Error with his job and keeping up his own end of the balance.

But looking at Dream now, he regrets not ever telling him, though the question of if he would even believe him gave reason enough to not tell him. He regrets not being there for what was happening to him now. But he resolves himself to help him now. He knows this is going to be awkward and difficult, but Dream is the new Destroyer now. He knows for a fact that Dream is going to struggle with his new reality, and he is going to start making up for his mistakes by helping Dream through this. Whether Dream wants it or not.

And that's the idea! Also, if/when Nightmare finds out that Error is alive, it becomes a new motivation to find Error to ask for help with Dream's new position.

Also, ever since I thought up this idea, I can't decide if it should be a part of Fgod!Error Meets Ccino or a different story. Because it could work very well for what I have planned in that story, but it works very well on its own.

What do you guys think?