The answers are C, D, E and F.
All these sentences present parts that are in some way a description of the devil : Sentence C describes the stranger's foul language and dark appearance. D: the weird expression getting darker and his three-forked thing (typical image of the devil). E: dark lightening-king. F: still travels in storm-time; drives a brave trade with the fears of man. (people's fears allow the devil to act boldly.)