Darius was satisfied with how things had gone with Pyrrha, happy that the former Goddess had so easily acquiesced to his demands. Manipulating her had been extremely easy, but given her nature, it would have been extremely embarrassing for him to fail.
A normal person might feel bad about tricking such an honest and upright person, but believe it or not, Darius was actually quite noncommittal about it.
That did not mean that he felt nothing. Perhaps because of his own innate character, Darius actually respected people like Pyrrha that most would describe as foolish and naive.
His personal view on them was that if only the world could be filled with more people like them, it would be a much better place.
Alas, the world, be it Earth or Faust, was filled with bad people, leaving those like Pyrrha with no other choice but to adapt like Darius had or get exploited until they died.