This is yet another example of someone confusing an epithet that was applied for a particular purpose with a nickname or sobriquet by which someone "was known".
Paganini's extraordinary skill with a violin is said to have given rise to rumours that he was in league with the Devil; Wikipedia states that his body was denied a Catholic burial for that reason, but fails to provide any citation for this claim. We surely need to be sceptical about how seriously those rumours were taken; there is no evidence to suggest that Paganini was known in his lifetime as "the Devil's violinist".
This was in fact the title of a film, produced in Germany, which was released in 2013 and starred the German violinist David Garrett (born David Christian Bongartz) as Paganini.
Paganini was also played by Stewart Granger in The Magic Bow (1946), Roxy Roth in A Song to Remember (1945), and Klaus Kinski in Kinski Paganini (1989)
Had the question asked "Which Italian violinist was portrayed in the 2013 film The Devil's Violinist?", I would not have complained.
© Macclesfield Quiz League 2019