John Wick 4's not-so-secret weapon is the biggest action star to join the franchise: Hong Kong cinema icon Donnie Yen.
As the blind assassin Caine, another old friend and antagonist of Wick's maybe-final chapter, he fills the screen with cool wit and lethal grace – a deadly Fred Astaire with a bladed walking stick who steals the movie each time he glides onscreen.
For lifelong martial-arts- and action-obsessive Chad Stahelski, asking the Ip Man and Once Upon A Time In China II star to join the John Wick universe was intimidating.
One of Asia's most successful crossover stars seen in Rogue One and Mulan, the actor, producer and director had turned down plenty of Hollywood roles before.
"I'm asking a bit of a life commitment, to put his life on hold for me, and it's not a 'Donnie Yen movie'," said the director. "We've invited him as a guest to our world. It was a bit daunting."
Yen, 59, only agreed if he could reshape the role, which Stahelski admits had been written with a "placeholder" details.
"The name was Shang or Chang," Yen told GQ. "Why can't he have a normal name?"
Stahelski appreciated the blunt honesty: "Donnie got the pages and said, 'I don't like the character. But I want to be in it. You want to work?'"
Yen found intriguing ways for his character to mirror Wick.
"He said, 'John Wick's cool. I want to be cool. I want to make this something that you and I haven't seen,'" said Stahelski.
"He gave me a great education of what Chinese audiences like, or what the Asian community might prefer more than just a stereotypical kind of role."
They arrived at a new name, Caine, with its layers of meaning: as a brother in arms to Wick's Abel; as nod to David Carradine's Kung Fu wanderer – and reclamation of Bruce Lee's reported exclusion from the role; and in the literal sense, the personification of his epee-like weapon of choice.
Yen sent the director an image of Bruce Lee in a skinny tie and suit, inspiring Caine's sleek look.
"We went off on this riff about Chow Yun-fat and how we both love John Woo and thought, 'We've gotta be as cool as Chow Yun-fat,'" said Stahelski. "If John looks that cool, Caine's got to look that cool."
Yen brought his own ideas to Caine's fighting style, folding fencing into his action vocabulary.
And for his most emotional scene, in which he duels with the wounded Koji – he and Sanada collaborated to create their own character-driven choreography.
"We tried to let the audience see: What are they thinking? What are they feeling? Why do they have to fight?" said Sanada.
"That's why I love the John Wicks so much – it's this nexus, this fantasyland, where you can have the legend of Hiroyuki Sanada, you can have the legend of Donnie Yen, and put them together to come up with something that hasn't been done," said Stahelski.
"If 14-year-old me could see that, he'd be like, 'Ahhhh!'" – Los Angeles Times/Tribune News Service