I got a chance to see the Orson Welles movie Black Magic over the weekend. The movie is basically a revenge film with some historical intrigue thrown in. Joseph Balsamo (Welles) is the son of gypsies traveling through the south of France. His mother is deemed a witch and executed along with his father by the Viscount de Montagne. Young Joseph is forced to watch his parents' hanging while he is whipped by de Montagne's men.
Years later, a grown up Joseph learns the secrets of hypnotism from a French doctor, changes his name to Count Cagliostro, and achieves fame throughout Europe by mixing hypnotism with mysticism and showmanship. As luck would have it, he stumbles across de Montagne who is hatching a plan to discredit Marie Antoinette and become ruler of France.
Cagliostro, of course, wants revenge on de Montagne. He starts of trying to help de Montagne achieve his goal, only to set him up to be captured and tried for treason. The courtroom scene at the end is a great showdown between Cagliostro and those who have influenced his life (both past and present). It shows Cagliostro's growing mania and the lengths he would go to to have the people of France love him. This sequence alone is worth the price of admission.
While Welles only acted in the movie, I could see some of his directorial flourishes in some of the early scenes. I took a quick look at Hello Americans, and Simon Callow mentions that Welles in fact did provide some input to director Gregory Ratoff. Count Cagliostro appears to be a role that Welles would've sunk his teeth into. He gets to play with a funny accent (like in The Lady from Shanghai) and a fake mustache. He also gets to show off a little of his magic skill in a couple scenes while talking to Akim Tamiroff (who later appears in many Welles films). But, he never seems to be fully engaged in the part. As Simon Callow notes in his Hello Americans, Welles was in the middle of editing Macbeth, so this seems to play into the idea.