Ezra Miller brings an electric energy to the superhero team-up film "Justice League,'' pinballing off the more imposing presences of Henry Cavill, Gal Gadot and Ben Affleck. They are mighty. He is fast. Miller was first cast as Barry Allen, a.k.a. The Flash, several years ago, but "Justice League'' is his most front-and-center performance yet as the fastest man alive. He's also the best thing in the film, adding a hyper, insecure liveliness that has often been lacking from many recent, more grandiose DC Comics films. As played by the 25-year-old, Barry is a motor-mouthed loner who, when asked by Bruce Wayne to join the League, is mostly happy to just have some friends. Miller, who has been credited as the first out LGBT person to play a lead role in a major superhero film, has distinguished himself by playing hyper-verbal outcasts in movies big ("Fantastic Beasts and Where to Find Them'') and small ("We Need to Talk About Kevin,'' "The Perks of Being a Wallflower''). Speaking by phone from London, Miller spoke with verbal gymnastics that even the Flash might struggle to keep up with. AP: From "City Island'' to "Fantastic Beasts'' you seem to be drawn to playing outsiders. Miller: I'm definitely interested in what I would call Barbara McClintock's discovery of the rebellious gene. Things advance by mutating away from their point of origin. I do think that happens on not just a cellular or genetic level but within civil society. A lot of the people who have shaped ideas and science on planet Earth have been outsiders. I feel often like an outside. It's a fascinating type of person to portray. And I think ultimately everyone has an element of that in their experience even if their life doesn't fully present that on first look. I think everyone can feel alienated and can both benefit by that and know the harm of that. AP: You seem a quick-witted person. Do you identify with the Flash? Miller: A cool idea about the Flash is that he, as he starts to move quicker and quicker with his body, he must also speed up mentally. When we shoot something in slow-motion, like we might on a Flash-inclusive movie, the way that's done is by rolling the camera faster. You shoot more frames per second when you want to slow down the image. In the same way, the Flash, as he moves faster, has to speed up to his brain in order to slow down his perception. That's all well and good when he's in superhero-mode, but one of the questions of our film asks is how does that play out in social circumstances? I think there are qualities that have been detrimental to his social capacity. AP: Were you at all concerned that a big production like this would leave less room for the kind of acting you practice? Miller: I feel personally that if I'm struggling for integrity, I'm already lacking in it. I come from a place where instead of trying to manufacture my standards of integrity I'm trying to work in such a way that I trust in that inherently when I step to any project, whatever the scale. I want to maintain the integrity of my process. Outside of that, forget about it. It's anyone's game. AP: But was there some appeal in bouncing off the more archetypal performances by Cavill, Gadot and Affleck? Miller: Yeah, that's one of the great joys. In a situation like this to have the immense gravity of everything — which I think is really maintained in this film — but then be in a situation where I can improvise. I can play. I can react in the way that I feel Barry might, in a way that can feel deeply human. That was exciting to me, the idea that in the age of superhero films in their absolute crescendo, you have this character who's sort of a fan who appreciates what he's witnessing. And to have someone who's having really human reactions to what's going on — to see a villain and have a panic attack — I connect with that. I think people connect with that. I think that's where we are. In terms of realizing our true potential as superheroes, the species on the planet, we're in amateur, novice stages. We are tripping over our own feet like Barry in this movie.