Question: What is similar about Mario Bava and Ben Holmes?

Context paragraphs:
Black Sunday (1960 film): Black Sunday (Italian: "La maschera del demonio"), also known as The Mask of Satan and Revenge of the Vampire, is a 1960 Italian gothic horror film directed by Mario Bava from a screenplay by Ennio de Concini and Mario Serandrei (with uncredited contributions by Bava, Marcello Coscia and Dino Di Palma), and starring Barbara Steele, John Richardson, Arturo Dominici and Ivo Garrani.  It was Bava's directorial debut, although he had completed several previous feature films without receiving an onscreen credit.  Based very loosely on Nikolai Gogol's short story "Viy", the narrative concerns a witch who is put to death by her own brother, only to return 200 years later to seek revenge on her descendants.

Lamberto Bava: Lamberto Bava (born 3 April 1944) is an Italian film director.  Born in Rome, Bava began working as an assistant director for his director father Mario Bava.  Lamberto co-directed the 1979 television film "La Venere d'Ille" with his father and in 1980 directed his first solo feature film "Macabre".

Mario Bava: Mario Bava (31 July 1914 – 27 April 1980) was an Italian director, screenwriter, special effects artist, and cinematographer from the "golden age" of Italian horror films.  His work kick-started the giallo film genre and the modern "slasher film".  His son Lamberto Bava later went on to become a noted horror film director in his own right.

A Bay of Blood: A Bay of Blood (Italian: Ecologia del delitto; also known as Twitch of the Death Nerve, Blood Bath and Reazione a catena/ Chain Reaction) is a 1971 Italian horror film directed by Mario Bava.  Bava co-wrote the screenplay with Giuseppe Zaccariello, Filippo Ottoni, and Sergio Canevari, with story credit given to Dardano Sacchetti and Franco Barberi.  The film stars Claudine Auger, Luigi Pistilli, Brigitte Skay, Nicoletta Elmi and Laura Betti.  Carlo Rambaldi created the gruesome special make-up effects.  The story details the simultaneous murderous activities of several different characters as they each attempt to remove any human obstacles that stand in the way of an inheritance of a bay.

Blood and Black Lace: Blood and Black Lace (Italian: "Sei donne per l'assassino" , 'Six Women for the Murderer' ) is a 1964 "giallo" directed by Mario Bava.  Bava co-wrote the screenplay with Giuseppe Barilla and Marcello Fondato.  The film stars Cameron Mitchell and Eva Bartok.  The story concerns the stalking and brutal murders of various scantily-clad fashion models, committed by a masked killer in a desperate attempt to obtain a scandal-revealing diary.

Knives of the Avenger: Knives of the Avenger (Italian: "I coltelli del vendicatore" ) directed by Mario Bava.  Bava entered production when it was already in falling apart and re-wrote and shot the film in six days.

Eugenio Bava: Eugenio Bava (4 June 1886, Italy – 23 October 1966, Rome, Italy) was an Italian film cinematographer and is the patriarch of the Bava family.  His son was acclaimed film director Mario Bava and his grandson is Italian horror film director Lamberto Bava.

Ben Holmes: Ben Holmes (November 6, 1890 – December 2, 1943) was an American film director and screenwriter.  He directed 56 films and wrote for 35.

Hercules in the Haunted World: Hercules in the Haunted World (Italian: Ercole al centro della terra) is a 1961 Italian sword-and-sandal film directed by Mario Bava.  British bodybuilder Reg Park plays Hercules while British actor Christopher Lee appears as Hercules' nemesis Lico.  Shooting at Cinecittà, director Mario Bava used some of the same sets from the earlier "Hercules and the Conquest of Atlantis" which had already starred Reg Park.

Planet of the Vampires: Planet of the Vampires (Italian: Terrore nello spazio, literally "Terror in space") is a 1965 Italian/Spanish science fiction horror film, produced by Fulvio Lucisano, directed by Mario Bava, that stars Barry Sullivan and Norma Bengell.  The screenplay, by Bava, Alberto Bevilacqua, Callisto Cosulich, Antonio Roman and Rafael J. Salvia, was based on an Italian-language science fiction short story, Renato Pestriniero's "One Night of 21 Hours".  American International Pictures released the film as the supporting feature on a double bill with Daniel Haller's "Die, Monster, Die! " (1965).

Supporting paragraphs: Mario Bava Ben Holmes
Answer: director and screenwriter