Superman Legacy, the movie that will mark the live-action rebirth of the DC Universe, has added three new actors to its cast, each of them playing a superhero with a long history in the comic books. Isabela Merced will play Hawkgirl, Edi Gathegi will be Mister Terrific and Nathan Fillion will portray a Green Lantern (although not necessarily the Green Lantern.)

James Gunn, who wrote and will direct the 2025 movie, has already cast David Corenswet (The Politician) as Clark Kent and The Marvelous Mrs. Maisel star Rachel Brosnahan as Lois Lane. When it starts shooting in January 2024, it will set the course for the new DCU that the Guardians of the Galaxy filmmaker is building in collaboration with fellow chair and CEO of DC Studios Peter Safran. 

In an exclusive to Vanity Fair, DC Studios revealed the new additions: Merced, best known for playing the besieged drug cartel daughter in Sicario: Day of the Soldado and the ever-exploring title character in Dora and the Lost City of Gold, will soar into the new universe as the winged warrior Hawkgirl. The hero's favorite battle accessories are melee weapons—swords, spears, and maces—and Merced's 5-foot-1 size will set her apart from the typical comic book brawler.

Gathegi, who played the double-dealing vampire Laurent in the Twilight films and the ever-evolving Darwin in X-Men: First Class, will take on the role of Mister Terrific, a.k.a. Michael Holt, who is not only a skilled combatant but one of the world's most brilliant inventors and tacticians, orbited by the floating T-Sphere weapons he designed. Among his superpowers is his otherworldly intellect. On the sleeve of his jacket is the phrase “Fair Play,” a tribute to the catchphrase of an earlier version of the Mister Terrific character as well as a statement of belief.

Finally, Fillion—a mainstay of Gunn's movies who starred in the director's first movie, the 2006 horror-comedy Slither, and his most recent one, Marvel Studios' Guardians of the Galaxy Vol. 3, will join him again in Superman Legacy as a Green Lantern named Guy Gardner. 

Comic fans primarily think of two primary characters in relation to the Green Lantern mantle. Hal Jordan was the original version of the comic book hero (played by Ryan Reynolds in the 2011 movie). The next iteration of the green glowing protector was named John Stewart, notable when he was introduced in the early ‘70s for being one of DC’s earliest and most prominent Black superheroes. Gardner, the character Fillion will play in Superman Legacy, is distinct from both of them for being somewhat less than heroic when he wears the matter-manifesting ring that gives the Green Lantern his powers.

Among the rest of the aliens and humans who serve in that group of galactic peacekeepers, Gardner is known as an abrasive, sometimes obnoxious presence. The role also brings a dose of awkward comedy to Superman Legacy. The character is known for his iconic bowl cut haircut, which will be a part of Fillion's look in the film.

While there is also a Green Lantern TV series in the works as part of the rebooted DCU, that one will focus on Hal Jordan and John Stewart.

Fillion previously played a DC character in Gunn's The Suicide Squad known as T.D.K., or The Detachable Kid, whose powers consisted of the ability to separate his limbs from his body and telekinetically launch them at his enemies. T.D.K.—spoiler alert—didn't survive for very long in that movie. So there's no danger of the actor's duel roles ever crossing paths.

That raises the enduring question of what DC movies and TV shows from the past will end, and which will be woven into the new slate of storytelling. While Superman Legacy is the first movie in the rejuvenated DCU, the first project in the new universe will be an animated series for the Max streaming service called Creature Commandos. 

Some characters from Gunn's previous DC work on The Suicide Squad will be grandfathered in to the new universe, such as Viola Davis' powerbroker Amanda Waller, who is getting her own TV series, and John Cena's Peacemaker, who was introduced in that movie and went on to star in his own self-titled TV show. A second season of Peacemaker will be part of the new DCU.

Gunn and Safran are selecting elements that will carry over, mostly based on actors. For instance, Gunn has said that Cobra Kai actor Xolo Maridueña, who stars in the upcoming Blue Beetle movie, will continue playing the character in the new DCU, but that upcoming movie will stand on its own. 

The new leadership of DC Studios has stated that their overall goal is accessibility that allows viewers to go into any of the future movies and shows without the need for deep binge-watching research. “The good news is, if you've seen nothing that we've done before, you can watch Superman Legacy, you can watch Creature Commandos, you can watch Peacemaker season two, and you can watch Blue Beetle. All of that," Safran tells Vanity Fair. “We are trying to minimize audience confusion and maximize their enjoyment.”