Prior to taking on the title role, Moon Knight star Oscar Isaac had reservations about returning to a big-budget franchise.

“Oscar was reluctant to accept the role at the beginning, because he came from such big projects like Star Wars and Dune and X-Men, and he wanted to take a break and make small films,” Moon Knight director and executive producer Mohamed Diab told The Hollywood Reporter at the show’s L.A. premiere event Tuesday evening. “But I convinced him that we can do that in our show.”

Today, Isaac seems to have fully embraced his role — or roles, that is — as the mercenary Marc Spector, a character who is granted the powers of an Egyptian moon god, while also struggling with dissociative identity disorder (DID). As a result of his condition, Spector grapples with multiple personalities, one of which is Steven Grant, whom Isaac also plays in the show.

“It was really about finding Steven for me first,” Isaac said of playing two different characters. “When I found this character that I just loved playing, then it was about finding the counterpoint to that, and obviously using the script and the comics to create Marc Spector — his identity, how he moves in the world — and then making those things as distinct as possible.”

As for which of the two characters he holds closer to his heart, Isaac didn’t hesitate to confirm his love for Grant. “He’s just so fun,” Isaac said of his character’s British counterpart. “I just love that guy.”

Ethan Hawke also makes his MCU debut as Moon Knight’s adversary Arthur Harrow, after Isaac, a longtime friend, convinced him to join the project.

“In truth, there was a fire in Oscar’s eyes,” Hawke said of his co-star. “When an actor comes at you and has the passion that he has, I knew he wouldn’t fail. And that combined with the fact that I’ve been following Mohamed Diab’s work for a long time, I had wanted to make another movie with him before this happened. And so it felt kind of meant to be.”

“Oscar lives down the street from me,” Hawke added about his friend. “And so it just felt right. I just trust my gut in these situations.”

Moon Knight approaches mental illness in a way fans have yet to see in the Marvel universe, with Spector’s condition being central to his character arc and development. It affects his day-to-day life, as well as his relationships to the people around him.

“Mental health is such a big part of the conversation now,” said May Calamawy, who plays Marc’s friend and possible love interest Layla El-Faouly in the show. “Marvel has always given us superheroes who are not flawless. They’re humanized in that sense. But with Moon Knight, it feels like the show follows the condition and what he’s going through. When it comes to situations that are difficult to talk about, like DID, it’s interesting to show it in a fictional light where it might be a little easier to digest and make sense.”

Added head writer Jeremy Slater of his approach to the show’s mental health aspect, “When you’re doing something for Marvel, you know millions of people are going to be watching and hyper-analyzing every frame. And so we knew we had to get it right, that we were dealing with important topics that are going to affect actual viewers, who we don’t know what they’re going through. It was really important to me, and all of my writers, that whatever we put out there into the universe has to ultimately be positive, and have an uplifting, positive message about mental health.”

As the MCU’s Phase 4 ramps up, Moon Knight steps onto the scene as part of a recent influx of newly introduced Marvel heroes including Shang-Chi, Kate Bishop (Hawkeye) and the Eternals. But why tell Marc Spector’s story now?

“The MCU has sort of earned the right to take those big swings,” said Slater of introducing Moon Knight at this stage in the game. “At this point, the MCU is the Star Wars of our day, for a whole new generation. I think if they had tried to do a character like Moon Knight early on, in the original Iron Man days, it would have been such a weird swing. But because we’ve opened up [the world] and brought monsters and magic and gods and aliens and things like that [into the MCU], I think audiences are going to be a lot more accepting of some of the weird places we go in this show.”

Added Hawke, “Part of the adventure of doing these Marvel things is that it’s a little bit like jumping off a cliff and trying to learn how to fly. We weren’t exactly sure what the show was before we started. We kind of came up with it together. It’s like, ‘swim or drown.’ So I’m happy with how it turned out.”

Moon Knight follows the formula of previous Marvel shows as a limited series with six hour-long episodes. Ultimately, it was Marc Spector’s emotional journey that lent itself to a series format, rather than a film, said the writing team.

“We can take bigger chances because of the show,” Slater said. “We can spend more time on this guy’s inner struggle and the emotional journey that he’s going on. And we don’t really have to worry about doing that big $200 million summer blockbuster. We can really do something that’s weirder and cooler and more experimental, and I think that’s what we delivered. You couldn’t do Moon Knight as a feature film and still have as rich of a character journey that Oscar Isaac is going to take people on.”

Moon Knight’s first episode premieres on Disney+ on March 30.