Although Dora had already shot his first feature-film, Debris Documentar, in 2003, his debut as director was marked in 2006 by Cannibal, a reconstruction of the case of Armin Meiwes, who killed and ate a willing victim whom he met on the internet.
Melancholie der Engel generated a lot of controversy because of many scenes involving rape, coprophilia, zoophilia, and real animal cruelty (although the murder of a cat was proven to be fake).
Pesthauch der Menschlichkeit was quickly dubbed as one of Dora’s most hardcore works to date, with many viewers criticizing its relentlessly cruel nature and extreme violence towards animals.
Dora's main influence is the European cinema of the 70s: he is a great admirer of the work of Italian directors Gualtiero Jacopetti, Ruggero Deodato, and Sergio Martino, as well as of composers Riz Ortolani, Pippo Caruso, Ennio Morricone, and Guido & Maurizio De Angelis.
Europe’s literary and poetical tradition is another major influence on Dora: many dialogues in his films contain references to the works of Johann Wolfgang von Goethe, Eduard Mörike, Georg Büchner, Marquis de Sade, Friedrich Nietzsche, and many others.
Dora has claimed that he is fascinated by serial killers like Charles Manson, Andreas Baader, Jeffrey Dahmer, and Dennis Nilsen, particularly their ability to manipulate other people in order to get what they want.