I get the point of playing weak, evil people like talking to the weak.
"If a man has you entirely at his mercy, then hope like hell that man is an evil man. Because the evil like power, power over people, and they want to see you in fear. They want you to know you're going to die. So they'll talk. They'll gloat. They'll watch you squirm. They'll put off the moment of murder like another man will put off a good cigar. So hope like hell your captor is an evil man. A good man will kill you with hardly a word." - Terry Pratchett, Men at Arms.
I think the last question about why spare one was the last question puzzling him so the going all out comment was he has now had his answers and it's time to kill you. Although it could have been done with less cliche line.