Trivia: Probably the most impressive visual effect in this film is when Corso consults the twin brothers Pablo and Pedro Ceniza (rare book experts). Both Ceniza twins were played by actor José López Rodero in the subtle and entirely convincing digital effect sequence. The only flaw was that the elderly twins had identical facial wrinkles, which never happens with real-life twins. Beyond that, José López Rodero additionally played the two nameless workmen that Corso encounters at the end of the film, meaning that Rodero played four digital-effect roles in this movie.
Trivia: Emmanuelle Seigner, who is playing 'the girl,' is actually the wife of the director Roman Polanski.
Answer: Lucifer was also known as the morning star. Depending on your view he passed the trial and was granted entrance through the ninth gate.