Christian teaches German Literature at the Bergische University Wuppertal, Germany (as Akademischer Rat and Privatdozent). He studied German Language and Literature as well as Sociology at the University of Kiel (Germany) and at the Freie University Berlin (Germany) where he also did his Doctorate in Comparative Literature. His PhD dissertation was a biography about the German author and playwright, painter and sculptor Ernst Penzoldt (2006). In this context he started to focus on the theory of biography and edited some fundamental volumes in German about theoretical questions concerning biographical research: Grundlagen der Biographik (2002) and Handbuch Biographie (2009). In 2014 he published his study on cult books (Kultbücher. Theoretische Zugänge und exemplarische Analysen). In 2015 he was DAAD-Visiting Professor in German Studies at Monash University, Melbourne, and received a fellowship at the »Morphomata Center for Advanced Studies« at the University of Cologne, Germany. In 2016 and 2017 he was Max Kade Visiting Professor at Michigan State University, and in 2018 he is Max Kade Visiting Professor at the University of Illinois at Chicago where he continues his works on Comics.
As a reader, he has been studying comics since childhood, reading Fix und Foxi, Nick Knatterton, or Tim und Struppi. In 2016 he published the first German-language textbook on comics (Comics und Graphic Novels – eine Einführung, with Julia Abel) and since then has written a number of articles on comics and graphic novels.