Doctor Doom's origin!

This film is evidently where Jack Kirby, the ultimate film-fanatic, drew his inspiration for Doctor Doom. Like Caliostro, Doom was a gypsy child whose mother was considered a witch and killed by the local aristocrocy. Further, Doom was scarred in a horrible fashion, as Welles' character was whipped nearly to death. Caliostro was amoral and possessed wisdom and powers with which he used to gain favor and revenge. As such so was Doom, who studied his mother's craft of sorcery and spent his growing up years bilking the wealthy with false cures and machinery.

Bill Finger gave us the Joker by way of Conrad Viedt in the Man Who Laughs.
Kirby contributed Doctor Doom as a homage to Welles' role in Black Magic.