SPOILER WARNING: The following article contains major spoilers for the season finale of "Avengers: Ultron Revolution."

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It's been a turbulent third season for the heroes of Marvel's "Avengers: Ultron Revolution." In addition to seeing the team deal with a season-long threat from the robotic Ultron, Season 3 has included the debuts of the Masters of Evil and their heroic counterparts, and the Thunderbolts, the time-traveling despot Kang the Conqueror. Along the way, the series introduced new heroes Captain Marvel, Vision, Black Panther, Ms. Marvel, Red Hulk and the superhuman race of Inhumans. With so many characters available to the show's writers and animators, there was only one way to bring the season to a close: all-out Civil War.

The four-part finale begins with the Avengers attempting to stop Maximus the Mad's plot to destroy the Inhuman city of Attilan. Things quickly go south when government liaison Truman Marsh enacts the Inhuman Registration Act that calls for all Inhumans to register with the government or be sent to prison. The Avengers are vehemently against this action, which leads to a government-sanctioned team of Mighty Avengers. Now, while the heroes are busy fighting among themselves, Ultron has returned to make his final move for world domination.

RELATED: Wacker Teases End of "One of the Avengers You Love" on "Ultron Revolution"

We spoke with Marvel Animation Vice President Steve Wacker and Director of Current Series Marsha Griffin to find out what makes "Civil War" such a versatile story, what motivated the use of the Inhumans, finding the right mix of comic book adaptations and original stories, and what viewers can look forward to in next season's "Secret Wars."

CBR: Marvel Animation has evolved a lot over the last several years; the Avengers moved from "Earth's Mightiest Heroes" to "Avengers Assemble," and other series like "Ultimate Spider-Man," "Hulk and the Agents of S.M.A.S.H." and "Guardians of the Galaxy" have added new characters to this shared universe. Steve, how have you seen the animation line evolve in your time as Vice President?

Steve Wacker: The benefit I had is, I came into a machine that Jeph Loeb had built. He knows what he's doing when it comes to television. So I walked into a really sharp set of animators led by Eric Radomski, who is our Vice President of Production. Really, the two of them built this machine, and when I walked into it three years ago my job was to help guide the shows creatively and help build the staff and continue doing stories that built up the animation side as strongly as we've seen the publishing division built up and the live-action division built up.

The fun I got to have was coming from the comic book side and bring a lot of that knowledge over here. I helped build our stories like "Spider-Verse" in "Ultimate Spider-Man," which was a real big success for us and is something that came from the comic books. We've done even more of that, including the current "Civil War" story that's going to wrap up "Avengers: Ultron Revolution."

"Civil War" closes out Season 3 of "Ultron Revolution," and we recently saw another adaptation from Marvel Studios. The television and film versions are vastly different from one another. How versatile a story is "Civil War?"

Wacker: Boy, that's a good question. I will say, you hit on something. By necessity, our version of "Civil War" is different. We had done a story similar thematically to "Civil War" in our previous season called "Disassembled," where the two core group of Avengers were at odds, so we've gone down that road.

Marsha Griffin, who is the executive overseeing "Avengers" Season 3, it was her job to take all the things I wanted to do and to work with our story editors, Dani Wolff and Eugene Son, to turn it into a story. Marsha is a former animation writer so she's had these problems before from the other side of the desk, and she worked creatively with our writers and animation team to take the things I had asked for, like all these new characters like Captain Marvel and Ms. Marvel and Black Panther and more. To take the Inhumans I wanted to lace throughout the season to end with a big "Civil War" story. I'll let her talk about the challenges of making a "Civil War" that was a little different.

Marsha Griffin: There's always the need. We always had the challenge to stay true to all of the mythology and all of the characters and all of the things that everybody knows and loves about the "Civil War" story. But we also need to keep in mind what the movies are doing. There's also the challenge and hope that we can put our own little spin on it so the fans don't just feel like they're watching something they've seen a million times before.

It's a great opportunity, the "Civil War" arc, to introduce new characters that were found in the movie, but find a way to introduce them to a new audience, because our target audience is fairly much younger, and this may be, for a great many of them, the very first time they are seeing any of these characters. Our challenge is to look at them in a fresh way and to introduce them in a way to young fans of the Marvel Universe. We looked at "Civil War" as a way to do that, as a way to bring Captain Marvel into their lives, as a way to bring Ms. Marvel into their lives. Trying to introduce new characters in a fresh way to a completely new audience and that was what we hoped to do.

I definitely loved how you incorporated so many of the different characters. Like you said, Ms. Marvel, Ant-Man, Songbird, everyone that appeared throughout the season.

Griffin: Right. We loved having the chance to meet them again for the first time. And they're all such fun characters. Especially Ms. Marvel, who our kids can relate to.

Wacker: Our shows air domestically on Disney XD, and we've worked hard to work with them as partners, with Marc Buhaj, the guy who heads stuff up there. He's asked for stories...he put the challenge out, stories we can plan events around. So these episodes are all airing together this weekend as a big four-part event.

And that's the kind of stuff Marvel does better than anybody. You want an event, we got one. Having this cap off the season, that put us in a strong position for Season 4 for "Secret Wars." It helps a lot.

We've announced "Secret Wars" right? [Laughs]

Yes, that's out there! I believe this is the first four-part episode for what used to be titled "Avengers Assemble."

Wacker: Yeah, you're right.

What are some of the benefits of doing long-term storytelling like this?

Griffin: The great part is a lot of times we have to handle storylines and major plot points in one episode, in two episodes. It's hard to tell a really epic tale in that amount of time. So having a four-part event allowed us to take our time, explore, and make everything as cool as we possibly could. We could really take the time to explore characters and motivations and really cool set pieces and battles between the two sides. So four parts give us room to breathe and room to have fun.

Wacker: To tackle your question from a different angle a little bit, the challenges with this big story and this happens on the comic book side, too. When you do a big event story like this is making sure everyone has a moment. It was very important to Marsha -- we've got so many heroes flying around here -- to take the time to give them moments that feel definitive, to give them arcs.

While the Inhumans didn't play a role in the comic and cinematic versions of "Civil War," they're front and center here. What motivated the use of the Inhumans, and what made them right for this story?

Wacker: I just love those characters. They are super-rich. We broke a lot of the big themes of the season, the big overview of the season -- Joe Quesada, our Chief Creative Officer, had some very insightful takes on them. I want to use our animated series as a way to introduce younger audiences to the rich library of characters we have. Our library has thousands of characters. I think for the bulk of our Marvel audience going forward, they're going to be introduced to these characters at very young ages. Because Marvel has become such a big, sort of idea out in the universe.

But the little kids, it might be hard for them to watch the movies and be able to absorb the context and even some of the live-action shows. I consider these animated series as a perfect entry point, a perfect gateway, into the larger library. So every season my hope is to introduce something new from the depths of the Marvel Universe that you or I might be very comfortable with and know like the back of our hand. But that younger viewers won't.

My kids are getting to know the Inhumans for the first time through this series. We get to see the Inhuman Royal Family in their element, and the story that feels like it belongs to them that they are a big part of. We'll see that in all of our series. Season 2 of "Guardians," for much of the same reason, we've got Warlock, which is a character nobody knows except you and me. Kids will get an introduction to Warlock and understand who that character is. I don't think any of us want to just be telling stories of the same seven characters when Marvel has so much to offer. Marsha is brand new to all of this, so she's a good filter for how to make it explainable to humans.

Griffin: I think the Inhumans, thematically, they also work for us because of kids. They look like everybody else, but they're different. They feel different, they have different powers, but sometimes it's not visible to the naked eye. Lots of kids feel different. There are a lot of kids who don't necessarily feel like everybody else. It shows how to embrace who you are and sometimes people don't always understand you but you're special. You have your own gifts and that also plays into the Inhuman story as well. Thematically, it's a great story for kids.

We see a new team of Avengers rise up (namely the Mighty Avengers) after the old guard disassembles over the Inhuman Registration Act. Is there room to have multiple teams of Avengers occupy the same space in Season 4?

Wacker: Oh, boy, that's a very good question. Okay, I'm just going to say yes. That's sort of where we started the season. Things go haywire pretty quickly. I think it's very important that so many personalities find a way of working together very quickly, bbefore the "Secret Wars" starts. That's going to be our real challenge.

In one of the episodes, we see a scene of Falcon holding Cap's shield. Was that a wink towards the comics, and could it lead to Sam Wilson becoming Captain America down the line?

Wacker: It was absolutely a wink to the comics. I love what Nick Spencer and the team are doing on "Captain America: Sam Wilson." As for Sam Wilson becoming Captain America, that would be telling I'm afraid. But that was absolutely a nod. If there are any benefits of me working here, it's my proximity to our publishing side. Even next week, I get to go to New York and hear the cool ideas coming from our comic books over the next year and a half, and find ways to reflect them in our animated series.

One that I'm fairly excited to hear about is "Monsters Unleashed." That has animation written all over it.

Right. There's a lot of potential with that.

Wacker: Absolutely. You'll see in "Secret Wars," if you're a Marvel Comics reader, you'll see many moments that you recognize throughout the season.

RELATED: SDCC: Marvel Announces Animated "Secret Wars," Skottie Young-Style "Rocket & Groot"

We've seen a few fan-favorite storylines from the comics adapted for the animated world. How hard is it to find the right mix of adaptations and original stories? What comic stories would you like to see adapted in the future?

Wacker: The big one for me would be "Superior Spider-Man." That was the last big story I worked on in the comics side with Dan Slott. I'm not quite sure how we get there, but I'd love to see it. I hadn't really thought about it, but our writers probably know coming in now that I'm going to want to see a certain amount of, "What can we pull from the comics? What are the things people know and love that we can really do our spin on and our take on and fit it into our shows?"

I'd love "Annihilation" on the Guardians side. I'm a big fan of the Darkhawks. Pulling that in would be super cool. I guess also, in a lot of ways, it's important to me that we don't just pull from the classic stories that people in their 30s like myself remember, but that newer comic readers might recognize. "Superior Spider-Man" is a good example. Not something pulled from something 40 years ago all the time, so we're not retelling the "Kree/Skull War" or "Spider-Man: No More."

There have been so many great Marvel stories over the past 10-15 years, real classics that I think will stand the test of time. It's fun to pull those in and, in some cases, like with our new Spidey series, and even on Avengers, we had Mark Waid come in and help toss ideas around. When you're doing it like that, you can bring people in who are really close to the characters. Another story we have coming up on the Spidey side...we'll get to "Spider Island" at some point. That was a big Spider-Man story in publishing. Certainly, "Secret Wars" that we're doing in Avengers is very close to what they've done on the publishing side.

Oh the Thunderbolts! We had the Thunderbolts this season. That was another big one. That's one of my favorite comics ever.

Songbird has been able to make herself into a hero.

Wacker: She's risen to the top, there. She's a great character. I'm such a fanboy for that [Kurt] Busiek/[Mark] Bagley run, especially that first issue. I can remember where I was when I got the first twist. I love pulling that stuff into our universe where we can. We're blessed with a group of story editors and they serve as our main writers. They hire freelance writers per episode but everything goes through their filter. On Avengers it's Danny and Eugene, who I've mentioned. They whip the script into the final shape and they're both Marvel readers and Marvel fans and do a great job of taking that Marvel DNA and resculpting it into something cool for animation.

During the four-part "Civil War" story arc, it's revealed that the man pulling the strings the entire time, Truman Marsh, is really Ultron in disguise. Is this the last we've seen of the robotic villain?

Wacker: I can't speak to the future, but it's the end of the season so yes. [Laughs]

Griffin: For now!

Wacker: For now, it is. I think it's fair to say that we consider this the ultimate Ultron story.

Griffin: There's always someplace else you can take it, but once we take it from unleashing the Terrigen Wave to creating an Inhuman army for himself and then turning that into wanting to destroy the entire planet and kill everybody, it leaves you with nowhere to go. At least, for now.

Tony Stark, with some magical help from Doctor Strange, sacrifices himself to stop Ultron. Tony's story doesn't end there, though. Why did you decide to take Tony off the board, and what does it mean for the Avengers moving forward?

Griffin: In terms of taking him off the board, it's such a gigantic arc and our characters have so much vested in it that in order to win, in order to defeat Ultron, it felt like it needed an equally massive sacrifice. In order to defeat him, it would not take something simple. It couldn't be an ordinary villain defeated in an ordinary way and we wanted our team to sacrifice something great in order to do that. We couldn't see anything bigger than taking Tony away from the team.

There was a lot of discussion on how we could do that. Would we eliminate him entirely? That didn't seem possible. We wanted to do something as dramatic and gut-wrenching as possible and that was removing him from the team and possibly barring him from ever coming back again. And maybe not being able to communicate. That's what we felt was necessary and I think dramatically it's really satisfying.

Clearly, we left it open at the end. Falcon finds a way to bring him at least back virtually to the team. What happens after that we'll have to find out in Season 4.

We talked earlier about how Season 4 will have the title "Avengers: Secret Wars." Can you give fans a tease of what to expect? Will we see a version of Battleworld?

Wacker: Yes. I will tell you that. We will see Battleworld. Much like this season, we will see a collection of stories that at first might seem like standalone adventures that we come to realize are all related to each other. We kick off the season with a focus on our new characters, including Ms. Marvel, Captain Marvel, Black Panther, Vision, Ant-Man and Wasp, and they become very important as the season goes on.

There is one little bit early on in the season that I think I've talked about publicly that I like a lot, and that's our "Agent Carter" episode. We were lucky to get Hayley Atwell to come in and do a voice and that sort of wraps a ribbon around the Peggy Carter/Cap relationship in a super emotional way.

Here's a scoop: our first story arc in Season 4 is called "Avengers: No More." That's all I can say.

Very ominous.

Wacker: That's a severe reaction to the end of Season 3.

"Avengers: Ultron Revolution's" "Civil War" four-part event will air back-to-back Saturday, January 28 starting at 11am on Disney XD.