Jazz Tangcay Artisans Editor Guy Nattiv‘s “Harmonia” has cast Naomi Watts, Vicky Krieps, Bella Ramsey and Odessa Young as Embankment Films, Range Media Partners and CAA Media Finance launch pre-sales ahead of Cannes. Inspired by a real-life events, the film is based on Nattiv’s grandmother and her involvement in an insidious cult.