A theory about the "real" world (spoilers)

[Acanthaceae]

We see in Verso's ending that he died on December 33, which means that the Dessendre world isn't our world.

The Manor wallpaper and flooring is very geometric, resembling typeface or even musical notation.

Perhaps the Dessendre world was created by Writer Alicia or Musician Verso.

[Apocalypse]

There certainly is the possibility of a war against the writers in the story, mentioned a few times. Now it could be the songwriters who wrote the tragedy of the Dessendre family.

Or it could be just a social thing with them fighting over art and reputation like different houses and guilds. Either way, that family is going down.