Luckily, Matt Reeves and Paul Dano both thrived on experimenting with scenes in “The Batman,” specifically how and when the Riddler would fly off the handle into one of his psychotic tirades. In fact, as The Guardian interview also noted, Reeves wrote the part with Dano as a performer in mind.
“There were all these moments as the Riddler where he’d be tickled by something and then fly into a rage, and you never knew from take to take where that switch would come,” Reeves went on. “I’d be sitting there with the headphones on, trying to stifle my laughter because he’d always do something surprising. Paul would ask me: ‘Was that crazy? Was that too much?’ I’d say: ‘No, it’s fantastic. Let’s do another.’”
Given how memorable Dano’s performance as the Riddler in ” The Batman” is, it seems like Reeves definitely made the right call by letting the actor take some big swings in his scenes. Being that the character is modeled after the Zodiac killer, it also helped to make him feel dangerous and unpredictable in precisely the way you want a Batman villain to be.