What did each one want?

[Of course she's going to focus on this.]

...I don't know how the magic worked.

But we talked to Mr. Ignatius' pieces, so that they realized they needed to be together to get what they wanted.

[It really wasn't that simple, but it is arguably what happened.]

Everyone's pieces were staying away from each other for different reasons... ....bringing them together means finding that, it seems.

['Seems' meaning....she wasn't there to see Sans go back together and well the OTHER two she saw split up are.

Still.

Split.]