Use "dastard" in a sentence

1. Does it mean he is still lurking somewhere inside our house, still bent on fulfilling his dastard mission of vengeance on an innocent friend, or did he too disappear, but how? No plausible answer was forthcoming

2. My client, an innately bashful man, would be the last man in the world to do anything ungentlemanly which injured modesty could object to or cast a stone at a girl who took the wrong turning when some dastard, responsible for her condition, had worked his own sweet will on her