Anthony Mackie recently told IMDb (via The Independent) about Ian McKellen’s wholesome reaction when he told him on the “Avengers: Doomsday” set that he was playing Captain America.

“I go to Ian McKellen, he goes, ‘Hello, son.’ I’m like, ‘Ian McKellen, sir. You’re amazing. It’s amazing to work with you,’” Mackie recalled. “He goes, ‘So what are you doing in the film?’ and I’m like, ‘I’m Captain America.’”

He continued, “And he goes, ‘Wonderful… and you deserve that.’ Thank you, Sir Ian, thank you.”

McKellen reprised his “X-Men” role as Magneto for “Doomsday,” which features a massive team-up of Marvel’s biggest stars. On the MCU side, returning cast members include Chris Evans, Chris Hemsworth, Danny Ramirez, Sebastian Stan, Paul Rudd, Tom Hiddleston, Letitia Wright, Winston Duke, Vanessa Kirby, Ebon Moss-Bachrach, Simu Liu, Florence Pugh, Lewis Pullman, Robert Downey Jr. and more. Several of McKellen’s “X-Men” co-stars are also joining the fray, including Patrick Stewart, James Marsden, Kelsey Grammer, Alan Cumming and Rebecca Romijn.

During a recent film festival appearance in Rome, McKellen said that while shooting an action scene in “Avengers: Doomsday,” the film’s directors, the Russo Brothers, told him to “look more furious” when acting out Magneto’s magnetic powers. McKellen said he envisioned destroying Donald Trump’s Florida resort, Mar-a-Lago, to inspire his rage.

“[They told me to] make it look as if you hate what you’re destroying,” McKellen said. “So I stood there and I shouted: ‘Mar-a-Lago!’”

“Avengers: Doomsday,” which hits theaters on Dec. 18, follows all of Marvel’s mightiest heroes as they team up to take on Doctor Doom, played by Downey Jr. in a switch-up from his iconic take as Tony Stark.

-Variety