Rowling noted that Grindelwald was mentioned in the very first "Harry Potter" book and had always been a background character, but remained very mysterious. And so, according to Yates, the cast and crew were continually developing and understanding Grindelwald throughout the course of filming.
"Obviously, the guiding principle was where Jo started, which was, he's a bit of a rock star," Yates said. "He's charismatic, he's beguiling, he's troubled."
He continued, "And so I wanted to see how witty he could be, how dangerous he could be, and how compelling and convincing he could be. And so we tried a lot of different ways of doing certain scenes."
Indeed, according to Yates, "there are probably three or four different versions of Grindelwald" because Johnny Depp would test out different mannerisms and line deliveries in each take.
"In fact, in earlier iterations of the edit, we'd show it to an audience and people kind of went, 'Yeah, I think he's got a point," Yates said. "The wizards are locked out and, you know, they're having a tough time and they want to be free. I get that.'"
The director continued, "And we were going, 'Oh my god, people are identifying with Grindelwald. This can't be right.' So we actually made him scarier."
Rowling notes in the extra that Grindelwald is an "autocrat" and a "sociopath," but he also has the ability to manipulate and seduce others with his charm and persuasive speech.
"Grindelwald has succeeded in an almost cult-like devotion in his followers," Rowling said.
Costume designer Coleen Atwood revealed that, for Grindelwald's style, she drew inspiration from Marilyn Manson and a glam-rock pop culture movement known as "The New Romantic." For his climactic rally, Yates told Atwood to dress the extras as if it were a rock concert.
Depp also appeared in the extra to discuss how he approached the role.
"It would be very easy to just go in and play a guy who's just play him evil," Depp said in the extra. "But one of the things that Jo and David and I talked about was that no one, no matter who they are or how horrible they are, how evil they are, they don't wake up in the morning and look in the mirror and say, 'Ah, I'm going to go out and do really bad things today.' No, he's doing what he believes is right at whatever cost."
