Supergirl Joins Man of Tomorrow’s Growing DCU Roster

Milly Alcock is suiting up again. The Supergirl star has been confirmed to reprise her role as Kara Zor-El in Man of Tomorrow, James Gunn’s Superman follow-up set to hit theaters on July 9, 2027. According to a profile in Variety, Alcock will be heading to Atlanta to join the production soon, with DC Studios co-president Peter Safran making no secret of how important she is to the bigger picture. “She’s a major part of what we’re doing,” Safran said.

That’s about all that’s been revealed — what Kara actually does in the film is being kept tightly under wraps. But the confirmation alone is enough to set the DC fandom buzzing, especially given how much the Man of Tomorrow ensemble has expanded in recent weeks.

A Superman Sequel That’s Starting to Look Like a Team-Up Event

At this point, calling Man of Tomorrow a Superman sequel almost feels like an understatement. The film’s confirmed cast now reads like a who’s who of the DCU: David Corenswet returns as Clark Kent, Nicholas Hoult is back as Lex Luthor, and Lars Eidinger steps in as the film’s central threat, Brainiac. On the hero side, Aaron Pierre is set to reprise his Lanterns role as John Stewart, while Edi Gathegi, Isabela Merced, and Nathan Fillion are all back as Mr. Terrific, Hawkgirl, and Guy Gardner respectively — three of the breakout characters from the first Superman film. Add Alcock’s Supergirl to that list, and you’ve got a roster that’s starting to look a lot less like a standalone sequel and a lot more like a full-scale event movie.

Gunn himself said as much last year, noting that Man of Tomorrow was not “a Superman sequel” in the traditional sense. Given that it’ll be the seventh entry in the new DC Universe by the time it arrives, most of these characters will have already been introduced in their own projects — which is exactly the kind of groundwork that makes a team-up like this feel earned rather than forced. That’s a very different situation than what happened with Batman v Superman: Dawn of Justice, which tried to cram a universe’s worth of characters into just the second DCEU film.

Adria Arjona is officially on board as Maxima, though some fans have floated the theory that the casting is a decoy and she’s actually playing the DCU’s new Wonder Woman. Jason Momoa is also rumored to return as Lobo following his debut in this summer’s Supergirl. And this month alone, the production added Scream veteran Matthew Lillard and Friday Night Lights star Sinqua Walls — both in undisclosed roles.

The Martian Manhunter Rumor Heating Up

Of those mystery castings, Walls’ has generated the most chatter. Insider Daniel Richtman has claimed that a casting grid associated with the project listed Martian Manhunter among the roles being filled, and that Walls’ recent addition may be connected to exactly that. “In a casting grid…it said they were casting Martian Manhunter, so I believe the recent casting was for that,” Richtman noted, though he added a caveat: “That being said, Gunn likes to call characters by other names on his grids, so we’ll see.”

Neither Gunn nor DC Studios has confirmed anything. But J’onn J’onzz — the Martian law enforcement officer stranded on Earth who becomes one of the Justice League’s founding members — has been conspicuously absent from live-action DC films for years. If Man of Tomorrow is the moment he finally shows up, it would be a very big deal for a lot of fans.

The Villain Bringing a Shakespearean Lens to Brainiac

While the hero roster grabs headlines, it’s worth paying attention to what’s happening on the villain side too. Eidinger — a celebrated theater actor making his biggest Hollywood splash yet — has been talking about his approach to Brainiac in a way that suggests Gunn is going for something philosophically rich, not just visually spectacular.

In an interview with The Hollywood Reporter, Eidinger described watching a rehearsal on set and having a moment of genuine awe: “I saw an actor in the Superman costume, suspended on wires in front of a blue screen. I looked at that image and thought: This is the essence of fiction. It’s as significant an image as Hamlet holding the skull: Superman, in that Superman pose, hanging from wires in front of a blue screen.”

He went further when discussing why superhero stories resonate with him on a deeper level. “These films have a serious philosophical ambition. They carry great allegorical weight for me. Take just the word ‘super’ — it’s used as a superlative, for something excellent, wonderful. But ‘super’ really only means ‘over’ or ‘above.’ So Superman is the Übermensch. You have the Super Ego. There’s already a deep psychological dimension built in.”

It’s a casting move reminiscent of Gunn’s choice to cast Chukwudi Iwuji — another theater-trained actor — as The High Evolutionary in Guardians of the Galaxy Vol. 3. That gamble paid off spectacularly. Eidinger, for his part, says landing in the Superman universe felt inevitable, even if it wasn’t something he’d chased. “Being in the Superman universe wasn’t a dream or burning desire for me. But now that it’s happening, I can see a certain inevitability in it, something almost fated.”

What Supergirl’s Role Could Look Like

As for Alcock, the timing of her Man of Tomorrow involvement is particularly interesting given that her solo film hasn’t even hit theaters yet. Supergirl — directed by Craig Gillespie and based on Tom King and Bilquis Evely’s acclaimed 12-issue miniseries Supergirl: Woman of Tomorrow — is one of Warner Bros.’ big summer releases, and early trailers suggest Kara’s arc centers on processing grief and trauma while stepping more fully into her identity as a hero.

If that’s where her character ends up by the time Supergirl closes, then being called upon by her cousin to help take down Brainiac in Man of Tomorrow would be a natural next step. Whether she’s a full supporting player or something closer to a substantial cameo — like Clark’s brief appearance in Supergirl — remains the question. But Safran’s language suggests it’s more than a glorified walk-on.

Gunn has consistently proven he can juggle large ensembles without losing the thread. The Guardians films gave every character room to breathe, and Superman managed to introduce Guy Gardner, Hawkgirl, and Mr. Terrific without overshadowing Clark’s own story. The bet here is that he knows exactly what he’s doing — and that every name on this ever-growing call sheet has a reason to be there.

Man of Tomorrow opens July 9, 2027.