It was that she was part of this secret society of ghosts known as the Reconciled who have found a way to keep from having their personalities degrade over time like normal ghosts do.
Traditionally in the lore, ghosts here are like ghosts in Supernatural and the Dresden Files. After rising, there's some part of them that is missing or perhaps being sequestered by whatever desire they're focusing on. And over time, they become obsessed with a singular desire until all of the rest of their personality ceases to exist. They'll reach a point that instead of avenging the death of themselves and their family, they are instead killing everyone and anyone just for kicks and giggles.
So they're also a lot like Hollows from Bleach in that respect.
The only two ways for ghosts to escape that fate are to either become Vampires or Reconciled. Vampires are ghosts who have possessed a living body and have devoured the original occupying soul, if I recall correctly. Although, I guess possessing a Hollow could work as well. But basically, they become anchored to the body and as a result, the decay stops. Originally I imagined as the two souls somehow become bonded but I think I've been told that isn't how it works.
The Reconciled have somehow found a way to remain pure ghosts, but without decaying as well.
This all goes into explaining the Church of Ecstasy and how it wants to destroy ghosts and instead find a way for normal humans to become demons, like the principal from Buffy.
And this is opposite the Path of Echoes, who apparently want all of Humanity to become super ghosts, and destroy the demon threat.
As a result, all three groups have a heavy interest in the Artifacts of Kotar(sp?), as it is believed that the artifacts can be used to destroy demons, empower demons, destroy ghosts, and enslave ghosts. So Carriless wants them to become a demon and/or destroy Setarra, the Church wants them to become demons and destroy ghosts, the Path wants them to destroy demons, and the Reconciled wants to destroy them to prevent them from being used on ghosts.
At least, that's how I think everything works out.
EDIT: I guess it should also be said that while on the one hand, while it was chronologically a "small" reveal, it was huge lore dump since most of this stuff isn't even in the rulebook. At least, it wasn't on release I don't think unless I just missed something massive lol.