The Ghost doctor sees evil and good as a mystery/riddle. She is the savior of all monsters as well as the nightmare of all monsters. The doctor works outside of this world, in a place where monsters exist, called Peach Capital. And as she tours around, she takes her little monk to go through the world while searching for the "hundred demon spectrum".
These are recommendation lists which contains
Hundred Demon Spectrum. You should give them a visit if you're looking for similar novels to read. Alternatively, you can also
create your own list.