A new human is donning the iconic Power ring in Green Lantern: Beware My Power. The animated film revolves around John Stewart, a Marine suffering from PTSD who has the iconic ring bestowed upon him and reluctantly joins a mission to discover the reason behind the Green Lantern Corps' disappearance.

Aldis Hodge, soon to make his live-action DC debut with Black Adam, leads the cast of Green Lantern: Beware My Power as Stewart alongside Jimmi Simpson, Nolan North, Jamie Gray Hyder, Brian Bloom, Keesha Sharp, Simon Templeman and Rick D. Wasserman.

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Ahead of the film's San Diego Comic-Con debut, Screen Rant spoke exclusively with co-writer Ernie Altbacker to discuss Green Lantern: Beware My Power, bringing John Stewart to the forefront, the film's controversial twist and more.

John Stewart in Green Lantern Beware My Power

Screen Rant: I am quickly becoming a fan of yours between Constantine, that we last spoke for, and now Green Lantern.

Ernie Altbacker: Well thank you, this one was a collaboration with John Semper and Jim Krieg in there too.

Last time we spoke, you jokingly threw out there that whatever we saw from you later this year probably was done two years ago. I'm curious, how did your work on this project come about?

Ernie Altbacker: You know, Krieg, every now and again — like maybe four years ago, Jim was like, "I think I want you and John for this, to do this movie." "Well, which one?" "I can't tell you right now." Then a year would pass and he would go, "Oh, yeah, this movie John Semper is on it." "With any character?" "I'm thinking it's John Stewart," and then a year would pass. [Chuckles] But then when we started to work on it, it was like done in three months, so there's a lot of talking and thinking before, and planning out the whole continuities and stuff.

So this is part of the Tomorrowverse, which only kind of kicked off a few years ago. What was it like really finding your story within this new arc that's being built?

Erie Altbacker: Well, you know, there's a lot going on in this one. Because when Jim started us down the path, he was like, "I want to do something like a cross between Hard-Traveling Heroes with the Green Lanterns, but also Apocalypse Now and the Heart of Darkness/Joseph Conrad adventure where they have to go up the river." And it was like, "Okay, this is gonna be a tough start." [Laughs] But we kind of figured it out and that's what made John Stewart such a good character in this is that he had the battle experience, he's scarred by it, he's got PTSD. And kind of just like Martin Sheen, he's got unfinished business out in the jungle. John Stewart has some psychic, unfinished business and he goes out into space and he goes through that crucible.

Since you mentioned the PTSD of the character, that was one thing I was actually really curious about, as off the top my head I couldn't recall any storylines from the comics of him suffering from that. Was that an original idea for this film, or was that something I'm not recalling from somewhere in in his history?

Ernie Altbacker: I don't know if I'm not remembering something, either, but no, we hadn't seen that anywhere. If you remember, John Stewart is in the Marines and then he kind of disappears and we don't know what he's done and suddenly, he's a Green Lantern. One of us said, "Well he had to be doing something during that time" and we said, "What if he was struggling during that time, struggling with getting back from Afghanistan and the horrors that he saw there?" And it kind of makes perfect sense.

I think it fit the story really well. What were your and John's biggest goals going into the development of this script?

Ernie Altbacker: Not to screw up. [Laughs] We just wanted to make the best story that that we could, have the best script so they can attract some great actors to voice the characters. I think the voice performances are excellent and the animation is very good. Okay, I'm sorry, you know what, I got a better answer than that, what was our goal? The underlying goal, and why this is a John Stewart project, is that we're kind of hoping that this project, in some way, can put John Stewart into the pantheon of great heroes where he belongs.

He was going on an upward trajectory with Justice League Unlimited and then he didn't really get involved in these animated movies, except around the Justice League table where he had a line or two or something. We're hoping that this is a coming-out party, and he gets used a lot more as far as in Justice League, and also with some solo adventures.

Hawkgirl and Green Arrow

That would be pretty exciting to see. How did you go about building the team that would be around him in the film?

Ernie Altbacker: We knew that we didn't want to put any of the trendy heroes in there, because then all of a sudden John Stewart is a passenger in his own movie, a bit part in his own movie. So we couldn't have Superman or Wonder Woman or Batman riding along on this one. It's just a nod, it's a nod to the classic Dennis O'Neil and Neal Adams Hard-Traveling Heroes comics run from the early '70s.

Your big twist in the film is really quite the big swing and, in your best spoiler-free angle, how did that come about?

Ernie Altbacker: We thought that it was needed — oh man, this is tough. [Laughs] We're hoping that the audience likes it. We know it'll be controversial, but we're hoping that the audience likes it and sees what we're trying to do, as far as putting John Stewart out in front.

I like it, I think the way you went about it really works in the film. We've got the film coming to Comic-Con, how are you feeling gearing up for its world premiere?

Ernie Altbacker: I'm excited, I'm excited about the world premiere. I don't think we're allowed to tell you about the exact date and time yet, but it'll be at Comic-Con and I believe that some of the stars in the movie will be there on the panel, hopefully we will too.

Have you been able to attend a Comic-Con panel for any of your past works in the comic book world?

Ernie Altbacker: Yeah, actually, for Batman: Hush I went through this process and then recently for the Constantine short film. A couple of them were gonna be [at Comic-Con], I think, were wiped out by the pandemic so that was a bummer, but I wasn't the only person who lost. There's a lot of great things that came out that we didn't get to premiere live, which is a bummer.

Constantine - The House of Mystery Director

Yeah, that's unfortunate what the pandemic did to the industry, but we're slowly getting back, so that's exciting for that front. Since you do mention Constantine, before I let you go, last we spoke was for House of Mystery and you mentioned you would have to wait and see how people responded to it for possibly continuing the storyline. Have you heard anything in the time since about possibly picking up from that cliffhanger ending that you left us with?

Ernie Altbacker: I can't say anything. [Laughs] I can't even say we're thinking about it, because then people will be like, "It's coming back!" I don't know. [Laughs]

Are you hopeful at least?

Ernie Altbacker: Yes, I am. [Chuckles]

Green Lantern: Beware My Power Synopsis

Green Lantern: Beware My Power

In this thrilling new DC Universe Movie, Earth’s latest Green Lantern will rise! When a Power Ring is bestowed upon former Marine John Stewart, it leads him on a life-changing mission. With Justice League member Green Arrow and Thanagarian Hawkgirl by his side, Stewart is thrown into a complicated galactic war with shocking origins and catastrophic consequences. It’s a trial by fire for the inexperienced Lantern as he battles deadly enemies like Sinestro – but a much darker secret will be the true test of this Green Lantern’s strength!

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Green Lantern: Beware My Power is now available on Blu-ray and DVD.