[Editor's note: The following contains spoilers for Black Adam.]

If you’re a fan of Henry Cavill’s Superman, the mid-credits scene in Black Adam was incredible. Not only did the scene tease his return to the DC universe, but it also opened up the possibility of Cavill’s Superman fighting Dwayne Johnson’s Black Adam in a future movie. And as a huge fan of Cavill’s portrayal of the Man of Steel, I could not be more excited.

However, while you might think the decision to put Superman in the mid-credit’s scene was a no brainer, consider the first Shazam! movie and how DC and Warner Bros. toyed with the fans. If you don’t remember, Superman does appear, but it’s from the neck down, so you have no idea who is in the suit, and I cannot express how frustrating it was for Cavill fans like me. I left the theater loving the movie and hating that scene.

Which brings me to my recent interview with Dwayne Johnson for Black Adam. I’d heard from multiple sources Johnson wanted Henry Cavill as Superman in the movie, but he was getting push back from the studio. For a long time, people told me Cavill would be in the mid-credits scene, or a cameo in the movie. But then I started hearing it wasn’t going to happen. It wasn’t until I saw the movie at the first press screening in L.A. that I realized Johnson had pulled it off and made the cameo happen. You have no idea how happy I was leaving the theater.

So, when I sat down with Johnson for an interview, the first thing I asked him was how it happened. After explaining how he and his team have been friends with Cavill for many years (his business partner, Dany Garcia, is also Cavill’s manager), he talked about wanted to give the fans what they wanted. But it wasn’t easy. He explained:

It got to a point where collectively, I want to say myself, Dany and Hiram (Garcia), we said, "Here's how the movie should end. And I'll give you one further, test it, and if it doesn't work, we'll never talk about it again. Test it." We shot it, to their credit, new leadership. They saw it and said, "We don't even have to test it."

As he says, it was the new leadership at WB that gave the greenlight to have Cavill return as Superman, which makes it sound like it was the previous regime at WB/DC that prevented it from happening sooner.

In addition to talking about Superman and how that happened, Johnson talked about the importance of doing right by the character and the mythology of Black Adam (which meant showing Black Adam killing people), why he wanted the awesome fight scene between him and Hawkman to showcase the superpowers that Black Adam has and to be able to show someone that can move incredibly fast.

Check out what Johnson had to say in the player at the bottom of the article, or you can read our conversation below.

Black Adam was directed by Jaume Collet-Serra and also stars Pierce Brosnan, Aldis Hodge, Noah Centineo and Quintessa Swindell. Black Adam was produced by Beau Flynn, Hiram Garcia, Johnson and Dany Garcia.

COLLIDER: Sir, I want to start with congratulations.

DWAYNE JOHNSON: Thank you, man.

I feel like I've been talking to you about this movie for 10 years.

JOHNSON: Yes.

And I can't believe I'm at the Black Adam junket talking to you about Black Adam.

JOHNSON: It's crazy.

It is. I have to start-

JOHNSON: Over 10 years.

It's been forever.

JOHNSON: Yeah.

Multiple set visits. Anyway, I heard you are the reason why something after the credits happens, I heard you were directly responsible and I wanted to know why it was so important to you, for that to be included in the movie?

JOHNSON: Sure. I am friends with that person, who we're talking about.

I'm trying to be, by the way, good for the people in the room that have not seen it.

JOHNSON: Right. So, the person that you're talking about, who's in Black Adam, that's the big surprise. That person, we are good friends. That person is very good friends with my business partner, Dany Garcia, who has worked very closely in advocating for his career over the years as manager. Hiam Garcia, our president, friends with that person. We've all known each other for a very long time, over 10 years.

When I have said to fans, "The hierarchy of power in the DC universe is about to change." I enjoyed saying that. It started some rumblings. Then I transitioned that to, "It feels like there's a new era in the DC universe that's getting ready to happen."

Now, that new era that I'm talking about, it wasn't just hyperbole to try and promote the movie. What I meant by that are a few things. Number one was we have an opportunity to really expand the DC universe. A universe that I love, I grew up a DC kid, you too. And I'm still a big ass DC kid. Like nothing's changed. So we have an opportunity to expand and introduce five new characters from the DC Bible, Black Adam and the JSA. And if you do your homework and you know your mythology, you see where some of the other characters of where we could go with them too.

Expansion. What it also means when I say there's a new era in the DC universe, what I mean by that is listening to the fans and really paying attention to them. And not just saying you're listening to them, but really listening to them. And what I have been a little frustrated with over the years is when fans speak up and they're saying something so loudly and no one is addressing them, and no leadership is stepping in and saying, "Okay, we hear you. Here's our plans, here's where we're going. You may not like it, but I respect you enough and we respect you enough. We're going to have dialogue."

It's been void of that. So when we do say that, when I say that, "This is a new era in the universe," it is listening to the fans. And we're not always going to be able to do everything that they want, but we are going to listen. So that the person you're talking about, the person you're talking about is a reflection of not only listening to the fans, but you got a guy who embodies Superman.

Listen, he is awesome.

JOHNSON: Yes.

In that role, it made me so happy and I know it's going to make so many fans happy. I could keep going on on this, but let me switch to something else. Something that I was nervous about going into the movie was that you've been on a family trajectory, you've been playing a certain role and I was nervous, "Will he really kill people?" And obviously you kill all the bad guys. You do not pull any punches. Can you talk about that aspect that this is the Black Adam that people... It is great to see you-

JOHNSON: He's ruthless.

Yeah. It was great to watch.

JOHNSON: Thank you, man. And well, that was a big deal for me because it was a real departure from anything that I've done in the past throughout my career. And if I was going to do right by the character and the mythology of Black Adam, Black Adam kills people, he rips them in half. He's brutal and he is ruthless and fueled by that rage of losing his family. So I ran to this opportunity to do this, not, "Oh, I just got to kill people." It was just more, "What a challenge this is?" So our director, Jaume Collet-Serra really helped me a lot in getting this character up on its feet. So I was very happy about that.

I'm already out of time. I'm just going to say-

JOHNSON: Go ahead.

Oh, are you sure?

JOHNSON: Another two minutes, go ahead.

Okay. One of the things that... By the way, thank you.

JOHNSON: And the reason why I want to do this is because even over 10 years ago, we had a conversation, I don't even remember this, but you said... Don't start the clock yet. But you were talking to Kevin Feige and you told Kevin back then, over 10 years ago... Where's Mia at? Are you here? So 10 years ago he said to Kevin, I didn't prompt it at all, and we had almost, maybe, just met, but he goes, "You know, someone who you should really think about being a superhero is Dwayne Johnson." Dude, I'll never forget that. It really meant a lot to me because you didn't have to do that, and I appreciate it.

I'm just going to point out to you that, and you won't remember this, and then I really want to ask a separate question about the movie. But on GI Joe, the sequel, you might not remember me visiting you on set and...

JOHNSON: I do.

...me convincing you to take a photo of all of us and putting it on Instagram so I could write that we were on the set of the movie. Later that day you did video of the vehicles. I was so happy because I'm like, "Oh, this is a great story." And it was the beginning…But let's go into this. One of the things that I love in the movie is the fight sequence between you and Hawkman and the apartment. It is brutal. It's shot in an innovative, cool way. It is unlike what you see in all the other superhero movies. Can you talk about filming that fight sequence and how innovative and cool it is?

JOHNSON: Yeah. So Jaume who is our director and he was really impassioned about shooting this, tight space. How do superheroes fight in this tight space? But then also it really allowed us on our end to showcase the superpowers that Black Adam has to the world. So, in terms of moving at light speed, he could punch Hawkman and before Hawkman even hits the wall, Black Adam could be right there on the other side. He's that fast. I really loved the fight that he was able to put together, that all of us were... It was brutal, but then also in those moments, I think it's just so badass to showcase just how badass Hawkman actually is.

That is a badass superhero, man. So, I loved all the Black Adam, Hawkman fights. I think we delivered for the fans on that. And across the board, I feel like we introduced all the characters nicely. What do you think?

I could do a longer cut. But I think Aldis is great as Hawkman and I think that the stuff between the two of you... I would love to see even more. I look forward to the sequel and I say this with all sincerity. Thank you for the after the credit scene, it meant a great deal to me. I think that that man is a fantastic... you know. And I just want to thank you because I really did hear it was directly you, for making that happen.

JOHNSON: It got to a point where collectively, I want to say myself, Dany and Hiram, we said, "Here's how the movie should end. And I'll give you one further, test it, and if it doesn't work, we'll never talk about it again. Test it." We shot it, to their credit, new leadership.

Oh sure. Yeah, exactly.

JOHNSON: Know who I'm talking about?

Yup.

JOHNSON: New leadership. They saw it and said, "We don't even have to test it.

Black Adam is now playing in theaters.