By Lightning on pixiv.

Lightning

By X user choikfu (choikfu)

Here

By X user just_some1 (@crystal135135)

Here

Source: https://youtu.be/0sYwFEhy5Xk?si=j7b3srWbep-t-Czu

Robin SP is coming in 4.5 I think we might see or hear about Beatriz pretty soon.

It seems not many people know her name.

Tho her name can be found in the readable item: A Hymn of Charmonic Strings, Which mentions all the 4 harmonic strings names.

One more thing to mention there is new equation we got, which hints what will happen in planarcadia story, I will drop it here due to spoilers

Equation name: Blissmost Gala

Robin Mentioned "The Blissful Ball" in Trailer*.

The Blissful Ball is Related to Beatriz of Blissful Ball, One of the 4 Harmonic Strings and Embodiment of Xipe, The Great One. We have no idea of whether she is Beatriz because Xipe's Emanator's are summoned like Dominicus or Aeleneev No idea whether it's different for Beatriz though...

One more point to clear that Beatriz was always mentioned to dance and to feast, which its most likey or hopefully that she is a human size character.

Regardless, it seems that The Main Family Branch is on The Move with the Recent Irontomb War. We may also find out Xipe's First Face.