Warner Bros. PicturesQuestioning the kill rate in a Zack Snyder superhero movie is nothing new, but with the furore that met Superman's pained decision to kill Zod, it was hugely surprising to see him have Batman so gleefully kill multiple enemies. Simply throwing out Batman's code is exactly as bad as ignoring Superman's code. In both cases, it would be an awful lot easier if they did, but therein lies their intrigue as characters. Apparently Zack Snyder didn't care for that approach. The component pieces were there of course - the idea that Batman had been transformed into a sadist by the ghosts of his recent past, but the explanation was left solely to the sight of dead Robin's costume, and it wasn't enough to explain the extreme shift.