So, Pencil and One. Both very major characters right now when it comes to the story of BFDI. They've done a lot in the series and we know quite a lot about them now. But.. it seems they're more similar than we thought. Even One herself points it out.

"I know how much you wish you could go back and change things with your friends. And no one can relate to that as much as me"

It seems like Pencil and One are parallels. Both of them have done something to tear apart the only friendships they had, losing who they cared about. And then they were thrown into isolation, forced to think about what they did over and over.

They both now try to fix what they did, desperately. They try to make up for it over and over, but instead they dig themselves deeper into their hole. They focus on their mistake so much that they refuse to move on and tear apart so many other things just to try and right their wrong.

"But it's too late for me, but not too late for you"

One saying that to Pencil seems.. strange. She doesn't seem to actually believe that. She's already gone this far for Three, to right what she did, I don't think she had a change of mind. I think she's still desperate to fix it. But I do think she's right.

It IS too late for her. She's going to cause so much harm that there isn't anyone that would forgive her. She'll hunt down every algebralien, one by one, and destroy their homes and all they know. Maybe even them.

Pencil though, she's gone far sure, but not irreversibly so. If she can look her past in the face, and accept what happened. Accept that she was a bad person and that she hurt people, then I think she can move on and find new people. There's so many other contestants and the failed debuters and etc etc., I bet she could find someone to be friends with.

"Y'know you can't fix anything, right? Match, Bubble, Book, Ice Cube. It's too late, you can't fix it. But if you redo it, you could."

One is definitely trying to manipulate Pencil here, but she does have some merit. Book and Ice Cube pretty clearly don't want to associate with Pencil and want to stay away from her. But Match and Bubble? Match still deeply cares for Pencil and considers themselves friends, and I bet Bubble probably feels similar. Pencil might not be able to resume her relationships with some of the Freesmarters, but that doesn’t mean she can't "fix" what happened. Yeah, she can't exactly fix it, but she could accept and respect Book and Ice Cube's choice and apologize for what she did and how it hurt them, before moving on. It wouldn't fix it, but it'd make their relationship a lot better then it is now.

I think if Pencil does try to redo it, it WON'T fix it. She could do everything right, but the fact that she's running from her mistakes and destroying the timeline just to fix what SHE did isn't good.

One has gotten rid of Blackhole so there's NOBODY to stop the rift, and since Pencil is messing up the timeline so vastly it's going to expand that rift. I think it'll come to a point where she either sacrifices the whole timeline and everybody else for her to live with her "fixed" version, or she comes to accept that what happened happened, and that she can't change it.

"We can both be free, Pencil"

But they never will be if they continue like this. Both are drowning in their guilt for ruining what they had, and are destroying everything else to "fix" it. The only way they WILL be free is if they let go, and try to move on. It's easier said then done but if they let themselves be held down by their guilt then how could they ever be free? Everything they do is in the shadow of their mistake. Pencil does everything either to avoid going back to the E.X.I.T. / Two's dimension, or to win back Freesmart. One does everything either as revenge to the other algebraliens, or to fix Three. Neither are free and their choices are determined by their mistake, or their trauma. Nothing else.