Marvel/Disney/Kobal/Shutterstock Chadwick Boseman and Letitia Wright in Black Panther (2018)
Wright, 28, played Black Panther's tech-genius little sister in the 2018 Marvel blockbuster, and she reprises the role in Black Panther: Wakanda Forever, which was filmed after Boseman's death from colon cancer in August 2020 at the age of 43.
Wakanda Forever costars Wright, Winston Duke and Tenoch Huerta spoke to PEOPLE at the D23 Expo on Saturday about honoring Boseman, who played the titular superhero, and expanding the franchise's scope.
Recalls Wright: "I will always have moments on set of doubt, and I'll be like, 'Oh man, I don't know if I can do this.' I could just hear [Boseman] be like, 'Sister, you're great. You got this. I'm proud of you.' That really just kept me moving forward."
"He was always a very quietly powerful person," Duke, 35, says of Boseman. "Sometimes you don't realize the extent, the amount of space people like that take up until they're not there. He was one of those people that led by example, and just led by always showing up and putting his best foot forward every day."
Corey Nickols/Getty for IMDb Letitia Wright, Winston Duke and Tenoch Huerta
Never miss a story — sign up for PEOPLE's free weekly newsletter to get the biggest news of the week delivered to your inbox every Friday.
"You don't realize that this movie wasn't as playful in between takes as the first one. When Chadwick was around we were rapping and laughing. It just wasn't the same dynamic," says Duke. "That's one thing we can tell you: It wasn't the same dynamic. But it couldn't be, because it's not the same circumstance."
"What it did have is a lot of love, a lot of inclusion," he says. "I think Black Panther has always been a really rich tapestry, and all the colors always make that tapestry grow."
Duke, who plays M'Baku in the movies, also opened up about how, still amid their collective grief, "finding the joy was really easy because you're surrounded by a lot of people that you like and the space felt very safe."
"The joy was at times very easy to find because you're also with people who are full of joy. And it just happens that we're dealing with a tragedy. We're dealing with immense loss of a person that we really loved and we knew as a person. Because we didn't know Chadwick as a figure on the screen, from far away, aspirational; we knew him as a friend, as someone's husband, someone's brother, someone's son, and a funny dude. It's very hard at times but really fun."
Black Panther: Wakanda Forever is in theaters Nov. 11.