‘The Punisher’ Star Jon Bernthal Explains Why Frank Castle Needs the Skull Vest

The Punisher star Jon Bernthal is adamant bullet-trading vigilante Frank Castle sports his famed skull vest for "tactical reasons."

"It's tough, I remember last year, there was a whole thing when he was making the vest, there was going to be a whole scene with Micro (Ebon Moss-Bachrach) where they're at the computer figuring it out. There was going to be the first time with him in the vest," Bernthal told Collider.

"He was just gonna sort of be drinking tea and I'm like, 'You can't do that. It's gonna look so friggin' stupid.'"

The bulletproof vest — long sported by Castle as a means of drawing fire towards the brazen, fear-inducing symbol that is the Punisher skull — is more than just familiar superhero iconography and is an essential tool in Castle's one-man war on crime.

"Look, man, these guys are superheroes and you got to somehow… to me, I'm really rigorous with the writers that if he's got to wear it there's got to be a tactical reason. There's got to be something behind it," Bernthal said.

"Because he's not a flashy guy. He spent season two of Daredevil laughing at Daredevil (Charlie Cox). Like, 'What the f— is with that costume? What's up with those ears?' We got to make that work. I actually feel like this year, when he puts it on, we figured out a very intelligent, very tactical reason, a very psychologically tactical reason to wear it. It makes a lot of sense."

Castle will need all the protection available to him as he battles the fanatical John Pilgrim (Josh Stewart) and old war buddy-slash-former best friend Billy Russo (Ben Barnes).

Work on the sophomore season of The Punisher proved so vigorous Bernthal was knocked unconscious and suffered a broken hand — just two of the many injuries earned by the battered star.

"I kept on fighting, and on day two I tore ligaments, then on day three I dislocated it and had to get emergency surgery. Was it the smartest thing to keep fighting with a broken hand? Maybe not. Maybe I could have been out for a shorter time," Bernthal told Men's Health.

"But I look at filming a scene like that the same way I look at a boxing match. I'm not gonna be the one to say I'm gonna walk away."

The Punisher debuts its second season January 18 exclusively on Netflix.