As per the Manual

Ms. Carnelia.
I still can't tell what kind of person you truly are.
I spent so long looking up to you and following the image you left behind.
I thought I would understand you by the time I was close enough to touch your shadow.
But... the moment I entered this place, you moved beyond my reach again.
The version of you I faced had become a traitor whose every act had been hypocrisy...
And now I can no longer tell what to believe.
...
This is exactly the kind of moment of being unsure of what to do, even after thinking it over through and through.
In fact... I might never understand, no matter how long I think about it.
The manual only tells us what to do, not about the means to understand.
...Claire.
That is why, as someone who once looked up to... No.
...As someone who was once the youngest maid. As someone who cared deeply for Carnelia.
I will do as the manual instructs.
No matter the situation... trust your fellow maid. Support them.
And if they stray from the right path, don't hate them.
...Once we're back, I will come to your aid.
To guide you back to the right path.
...
Fufu... I must have been quite fragile back then to write something like that.
...Carnelia.
See us in the real world. And when we do, we'll talk again.
Claire and I will come for you, whether you're in the Astro Sanctum or anywhere else.
...It would be nice if that were possible...
...Actually, no.
Perhaps I should hope for that as well.
After all... we'll have so much to talk about.
As I said, this world consists of various remnants.
And among those remnants...
There is also Dissonance.
...Dissonance?
The Light of Dawn, artifact of the Master Maid, originally held the power to attune.
It allowed power to be stabilized, preventing instability from spiraling out of control.
...But the Witch of Favoritism... reversed that power.

The Light of Dawn, symbol of the Master Maid, possesses the power to attune the Heart of the Star.
An artifact that keeps the Heart of the Star under control through stability and balance.
But...
Imagine if it became the exact opposite.
What if it ceased to attune... and instead brought Dissonance?

The power I used in Aganon to break the Heart of the Star and awaken Mogulus... was Dissonance.
...
The power of Dissonance still lingers in both my journal and the projection of the past.
Of course... it hadn't reacted until now.
You mean, just as Bell and I entered this world through your journal...
The Dissonance left in it has awakened too?
To be exact, the unstable memories and thoughts of the version of Carnelia lingering within this realm...
...have amplified the Dissonance to grow stronger the closer I came to NOA.
And now...
It seems that the remnants are trying to become the owner of this place.
What?! Wait a second...! How many times has this place shaken already?
Ms. Carnelia!!
Once that self-proclaimed owner is defeated, both of you should return to reality.
That said...
...I wanted this world gone as well.
Allow me to lend you a hand.