There is a discussion on my blog about Satan being the father of lies and murder. Murder is a lot worse than lying, obviously, but I make the argument it is only necessary to tell the truth when the person has to know it. And some people tell the truth to hurt people. I've seen it.
Let's take a fictional example in Breaking Bad. Jesse is hiding under a car and Walt tells the truth and turns him in.
After Jesse is captured, Walt again tells the truth and tells Jesse he watched Jesse's girlfriend, Jane, die.
Both of the things Walt did was to hurt Jesse. He told the truth to hurt Jesse.
When you tell the truth to sadistically hurt people, that is devilish.