Note the identification of the film as a giallo and the use of the colour yellow to strengthen this association.
Also note the retitling of the film as a body count movie: Five Victims for the Killer. This contrasts with the more literal translations used in most other territories, as The Sorceror or The Wizard.
The obvious reference point here is, of course, Six Women for the Killer, better known as Blood and Black Lace.
According to the IMDB the Italian film had its domestic release on 14th March 1964 and its West German release on 27 November of that year, while The Hexer had its domestic release on 21 August 1964; Unfortunately the IMDB doesn't have an Italian release date for Bava's film.