Solid characters but muddy world-building

The author has an excellent writing style, instantly hooking me with the opening pages. There's a great setup here for a girl-power ensemble adventure, and I look forward to seeing how it plays out. While I was sold on the characters, I was less sold on the world-building, which seemed a bit muddied and poorly explained ghosts are real, and some people have shadows and others don't? Hopefully the full story fleshes out this world a little better.