Démon ex machina (Maman Contre Démon)

The demons in 'Demon Ex Machina' feel fresh and complex, blending myth with original ideas. I'm curious what influenced the author's take on these supernatural beings.

The book balances supernatural battles with a suspenseful whodunit, but I felt myself more drawn into the investigation. Was this intentional or just how it unfolded for others?

The mix of genres kept things unpredictable, but I wonder if the dual focus was planned from the start or developed during writing.