CANNES: Barbet Schroeder spent months with Ugandan dictator Idi Amin at the height of his power, when corpses would wash up every morning on the shores of Lake Victoria and Kampala was rife with rumors that he was eating his opponents.

But in his decades of documenting evil, the veteran Swiss filmmaker said he has never been as scared by anyone as he was by a Burmese Buddhist monk named Wirathu.

“I am afraid to call him Wirathu because even his name scares me,” the highly acclaimed director told AFP. “I just call him W.”

“The Venerable W,” his chilling portrait of the monk who has been accused of preaching hate and inciting attacks on Myanmar’s Muslim Rohingya minority, has been hailed by critics at the Cannes film festival as a “stirring documentary about ethnic cleansing in action.”

What dismays Schroeder is that Wirathu, whom Time magazine dubbed “The face of Buddhist terror” in a 2013 cover, is utterly unfazed by the chaos and suffering he has unleashed. But the hate speech and fake news that Wirathu spreads from his Mandalay monastery, accusing Muslims — barely four percent of the country’s population — of trying to outbreed the majority Burmese, made Schroeder’s head spin.

This month, Wirathu — who has been called the Buddhist bin Laden — stirred tension by touring Muslim areas in troubled Rakhine State despite Myanmar’s top Buddhist body banning him from preaching in March.