Marvel's Captain America: Civil War..L to R: Hawkeye/Clint Barton (Jeremy Renner), Scarlet Witch/Wanda Maximoff (Elizabeth Olsen), Captain America/Steve Rogers (Chris Evans), and Winter Soldier/Bucky Barnes (Sebastian Stan)..Photo Credit: Film Frame..© Marvel 2016Black Widow vs. Hawkeye. Winter Soldier vs. Black Panther.

Those are just two of the kick-punching battles we saw last summer on the set of "Captain America: Civil War," Marvel's third Cap movie that, according to directors Anthony and Joe Russo, will forever change the Marvel Cinematic Universe when it hits theaters this summer.

Ever since Kevin Feige first announced the project in the fall of 2014, audiences have been figuratively (and sometimes literally) salivating at the prospect of watching two of their favorite Avengers duke it out and raise the emotional stakes of the franchise. But, why exactly are they fighting? Because of the Superhero Registration Act. It's a policy in reaction to Ultron's whole "Gonna kill Earth by throwing a city at it" plan in "Avengers: Age of Ultron;" something to help hold the heroes of the world accountable when their efforts to save the planet end up hurting it and its citizens.
Steve Rogers is against the Act. Tony Stark makes himself the public face of it. Fist-powered disagreements ensue. But the filmmakers promise that the only thing more impactful than the body blows our Avengers deliver are the emotional wounds they inflict -- which cut even deeper.

"[These movies] only work, the cool fights and action scenes, they only work if you care about the characters," Joe Russo said during a break from shooting a portion of the aforementioned fight, which takes place on the tarmac of a German airport. Here, Team Cap (above) assembles before engaging Team Iron Man in a battle that the Russos described as their version of a comic book's "splash page" -- a colorful two-page spread used to usually depict an epic action-y event.

Expect "Civil War" to have many of these moments, according to the members of Team Cap that we spoke with on set in Atlanta. To kick off the premiere of six new "Team Cap" posters, and the first part of our set visit coverage, Moviefone sat down with Chris Evans (Cap), Sebastian Stan (Winter Soldier), Jeremy Renner (Hawkeye), Elizabeth Olsen (Scarlet Witch), Anthony Mackie (Falcon), screenwriters Christopher Markus and Stephen McFeely, and the Russos to discuss the MCU's biggest movie yet. Here are 25 things we learned, as broken down by key players on Steve Rogers' team.

Anthony Mackie
1. Falcon serves as the "in" for the audience. "[Falcon is] being used strategically to ask the audience's questions," Mackie revealed, adding that Falcon illustrates this in ways similar to the scene in "Ultron" where Hawkeye pulls Scarlet Witch aside in the middle of the final battle. "He says 'Look, we're adults. I'm wearing a suit. I have arrows. I'm not cool, but we have to go out here and fight.'"

"So [in this movie] when Scarlet Witch is all (does rave hands) I'm like, 'You saw that? Right. Just making sure you saw that.' Scarlet Witch and her crazy rave baby technique and Ant-Man and him riding an ant. Alright, cool. That's what he does -- he shrinks and rides ants."

2. Speaking of Ant-Man, as seen in the film's trailer, Scott Lang becomes a member of Team Cap. And we saw him in action (well, just running with Team Cap toward a confrontation with Team Iron Man). We also saw Paul Rudd shooting a sequence that indicates Ant-Man gets his own "giant" (hint!) moment during the fight -- something we only glimpsed before being whisked away by on-set publicity.

3. Falcon's addition to the Avengers' roster at the end of "Ultron" is something "Civil War" will address, says Mackie: "The idea of him becoming an Avenger is pretty cool. He's pretty excited about it. We definitely get an element of that in the film." Mackie also stressed that the Russos have a "very specific" vision for Falcon's storyline and "how he feels about Steve and the rest of The Avengers."
4. Mackie is also excited about his character's new Avengers status, which he didn't become aware of until the premiere of "Ultron." "By the end of the movie," Mackie said, "I turn around and [Cap says] 'Avengers Assemble!' I'm like, 'Holy sh**! I'm an Avenger!' So I turn around to everybody with me and they were like, 'Dude! You're a f***in' Avenger!' That's the story of my Marvel life."

5. The Avengers' costumes, including Falcon's, get an upgrade courtesy of Tony Stark. And when it comes to Tony, according to Mackie, Falcon has a unique opinion about the billionaire-playboy-philanthropist.

"I don't know why everybody thinks Tony's cool, and Tony thinks he's really cool, but Falcon just thinks he's a nerd. And not like a cool millennium nerd." In addition to Falcon reacting to, and interacting more, with Stark, fans can expect to see Falcon assess Vision as well. "He is by far the easiest person to make fun of," Mackie says of Stark and Ultron's creation. "Vision is definitely my one guy because he's easy to make fun of."

6. Mackie also revealed that Falcon's costume is less cool on set than it looks on the big screen. That's because his character's wings are added later with CG. "They have these little wings [I wear on set], like these little three-foot wings. It's whatever. I'm happy about it. I'm happy to be an Avenger!"

Writers Christopher Markus and Stephen McFeely
7. As Tony and Steve battle it out, the writers revealed that Vision is primed to struggle with what it is to be human. As he was created to be a perfect being, now working with very flawed people, Markus said audiences can expect Vision to "have problems with the modern world." But the writers don't want him to deal with these problems in a cliched way. Rather, they want to address it similarly to how they dealt with Cap being a man "out of time" in the last film.

"In the same way that, in 'Winter Soldier,' we didn't want Steve to have trouble with iPhones and tight jeans, you know, like, 'what is this modern world?'" McFeely said. "But we wanted him to have problems with the modern world, right. We also don't want to do, with Vision, [in robot voice] 'How do I become a human?' So we're trying to be really elegant about this guy, who was one day old at the end of 'Ultron' adjusting to life."

8. And yes, fans, the relationship Vision and Scarlet Vision have in the comics will be addressed somewhat in "Civil War." "We play with it," Markus revealed. "It is kind of fascinating. But he's got the stone in his head that I think Strucker used to give [Witch] her powers. So it's all sort of, 'These things are getting really weird.' So there's fun toys to play with there."9. Another dynamic the writers are playing with here is Black Widow's relationship with both Stark and Rogers. As seen in the Super Bowl spot, Black Widow is on Team Iron Man -- but it's not easy for her.

"It's difficult," according to Markus, "because she's not trained to take sides. She's trained to be a duplicitous double-agent and have loyalties for sale. Obviously, she's well on her way to not being that person, but it's still... standing up next to someone and taking a side and going 'No I believe in this' is counter to her nature. So it's in a way almost toughest for her than anybody to go, 'This is my side and I'm sticking to it.'​"

10. In terms of "choosing sides," the writers hope audiences walk away from the movie as divided as the heroes in it. "We want people walking out of this movie going, 'Tony's right," McFeely said. "And half the other people going, 'Steve's right.' That would be a dream if we got 49-51 split. Because the question is a legitimate one. Do they need oversight or not? Steve, at one point, he says in the movie, what if these people send us somewhere we don't think we should go? What if there's a place we need to go, and they wont send us? It's an excellent argument."

11. In terms of locations, "Civil War" is an international affair. Markus revealed that the movie takes place "all over the world," in more locales than any previous Marvel film. He also teased we will visit at least one place from Captain America's past that we have seen before.

Directors Anthony and Joe Russo
12. When it comes to sheer scale, Marvel has outdone themselves here.

"This is much, much bigger than 'Winter Soldier,' Joe said. "I think it's probably bigger than anything they've done to date. Just scale of character, without question." His brother Anthony adds: "It's also very complex on that level because, again, while these characters have had conflicts before, this movie takes it to an entirely different level. The movie is very challenging, but very exciting to us on that level."

13. That splash panel fight mentioned above? It runs 15 minutes, and is the first IMAX sequence the directors shot for the film. And yes, you will want to see in glorious, brainsplodey IMAX.

14. That sequence also marks the first salvo of the war between heroes, according to the Russos. And while the teams are divided here, the Russos teased that the line-ups aren't permanent. "The movie kind of evolves," Anthony said. "There's a moment in the movie where this [line-up] is the division."

15. Much like "Three Days of the Condor" inspired the directors on "Winter Soldier," they turned to other films to help them create the "psychological drama" underlining "Civil War." Those films include: "Seven" (!?), "Fargo," "The Godfather," and some De Palma.

16. The directors are very impressed and satisfied with Chadwick Boseman's take on Black Panther.
"He brings real gravitas to the role," Joe said. The scene we saw being filmed was the first day that the character appeared on set in costume. And when the actor came out on set, according to Joe, "there were some comic book fans here who were just tearing up. It's a real moment for people to see this character for the first time on screen."

Joe added that Boseman is "playing the character with a real intensity and a real grace. He's got a movement style that he brought because he has a background in martial arts and it's fascinating. He moves like none of the other characters in the universe. We really distinguished him."

17. Of all the characters appearing in this film -- and there are a lot -- Black Widow and Black Panther proved the most challenging (and interesting) for the directing duo.

"We made some strong choices with Natasha in this movie, and it's a tricky arc that she has to play in the film," Joe said. Anthony added that the challenges with Black Panther center on him "entering the movie
as an outsider, and there's a lot of conflict surrounding him in the film. There's a lot of tension around that, it's great dramatic tension. It works great on a story level, but it's intense."

18. One character they remained very tight-lipped about was the inclusion of Spider-Man. Arguably the worst kept secret in Hollywood is that the new Spidey will make his first appearance in the MCU courtesy of "Civil War." But when asked how that will happen, or whose side Peter Parker will be on, the directors dodged it with a smile.

19. They had no problem, however, revealing that Black Widow and Scarlet Witch share a scene together. In fact, their scene together opens the movie.

20. The Russos also dropped something Vision fans will be very happy to see: Vision will appear in civilian attire. Joe said that figuring out that aspect of the character "was a fun conversation because he sort of projects his own clothing so it's an interpretation of his personality. He's rather dashing. It looks really good."

Chris Evans and Sebastian Stan
Marvel's Captain America: Civil War..Steve Rogers/Captain America (Chris Evans)..Photo Credit: Zade Rosenthal..© Marvel 201621. While the relationship between Cap and Iron Man drives the film's core conflict, it's the dynamic between best friends Cap and Bucky that serves as the film's beating heart, according to Evans.

"This is a huge relationship. This is a huge piece of [Cap's] history, it's a huge piece of his struggle, just the guilt that he must have [over losing Bucky]. So there's plenty to play with."

22. The last time we saw Bucky, he was inside Cap's museum -- staring at his own section of it. So where do we find Bucky when "Civil War" starts? The actors (shocker) wouldn't say. But Stan did tease this: "Whatever notions you had about that post-credits scene, where you see him in the museum, and obviously he's staring at himself -- whatever ideas you got from that scene, keep thinking about those and go with your own thoughts on that." Um, okay. Thanks. Good talk, bud.

23. Of all the Avengers Evans' character shares screentime with, the actor revealed his favorite: Black Widow. Fans can expect their relationship in "Winter Soldier" to grow even as they initially find themselves on opposite sides of the conflict. "I've grown to really like my scenes with Scarlett," Evans said. "Something about that relationship, because I don't think it drifts into a romantic place. I think it's a place where we each just need somebody. She's kinda been a loner for a long time and probably avoided friendships for professional purposes. And I had no friends because I was frozen. And now it's like a really nice brother and sister bond. There's some nice scenes in this one."
24. When asked how the rest of the Avengers respond to Cap's need to find Bucky, considering he was working as an assassin for HYDRA, Evans answered: "They sympathize. Cap's done nothing but give himself to this group, so I think they understand the value of what it means to Steve to find him. And especially after [Hawkeye's] been brainwashed, [Black Widow's] been misled, we've all had our share of being taken advantage of, so I don't think they hold [Bucky] completely responsible for some of his actions.

25. Evans is very excited about how the movie pairs off certain members for battle, promising that the Russos have created action scenes that rival the exceptional set pieces seen in "Winter Soldier." "These fights are not gonna be boring," Evans promised. "The way the Russos shot it, It just felt good. I think they're gonna outdo themselves on this one. There will be a lot of team combats."

You can see all those not-boring fights for yourself when "Civil War" hits theaters May 6.