It's always got to be difficult to cast a role in an iconic franchise like Fantastic Beasts And Where To Find Them. It must be that much more difficult to cast a role that's already had a very popular actor in it, which is the case for the character of Gellert Grindelwald, as previously portrayed by Johnny Depp.
TW: This article contains depictions or discussions of domestic abuse and may be triggering to some readers.