Dark and edgy themes popped up for some of the writers while filling in the "thematic bubbles" exercise. Because of that (cause and effect), those same writers willingly risk embracing darker and edgier themes which in turn creates darker and edgier character goals with clearer emotional weight and more unique and compelling heart to their stories, sending their stories to higher degrees of originality and mass appeal to all other books in their genre and beyond. Nearly every single writer discovered deeper elements about their stories that elevates their story concept.
Give the exercise a try. List all the themes in your story. Circle the themes that begin in the beginning (first page?) all the way to the end. Study those themes for meaning.
Today I write.
For more: Read my Plot Whisperer and Blockbuster Plots books for writers.