What did you see someone do to be called a cruel bastard?

I think of my ex. He has extremely poor anger management and can't control it. I've seen him punch walls, and even got to the point of taking his brothers glasses off his own face, breaking them, and shoving them back in his face just because his brother made the campaign in DnD not make it go the way he wanted. When he was little he apparently pulled kitten's tails hard enough to paralyze them and then burn them. The cruelest bastard I know.