2-2.5. It nabs a bunch of bits from 'The Exorcist', right down to the demon vomit, but the film actually has a good lead actress and the first half builds some interesting atmosphere. Specifically the scene wherein the desperate crowd is walled off from the visibly indifferent virgin Mary. But its unique touch sort of bleeds off when it goes into the loud, overwrought supernaturalism typical of exorcism stories.
Carla Gravina is a gorgeous actress here with her tasks of versatile tender/harsh moods. Mel Ferrer is wooden and monotone. The plot rides The Exorcist big success.. but as a vintage italian feature it's really tasteful.