Editor's note: This is the third in a weeklong series of interviews from an April visit to the set ofGuardians of the Galaxy Vol. 2 ... now just three short months away.

Nebula was supposed to be a bit player, a sibling-rivalry sideshow at best, when Karen Gillan signed up for an eight-day shoot for Guardians of the Galaxy. She's about to become a full-blown Guardian herself.

Of all the things we learned during an April visit to the shooting set outside of Atlanta, perhaps the most surprising was that the Guardians are expanding -- and that Nebula, the other daughter of Thanos, sister of Gamora and sworn enemy of the ragamuffin space gang will (eventually) be one of them.

That doesn't mean that the sister-on-sister violence between the blue and green factions of Thanos' offspring is coming to an end: "That's how they communicate, through fighting," Gillan told a group of reporters during a break in filming. And there will be fighting.

Gillan is a study in stark contrast between actress and character. The infectious, sunny ebullience that made Amy Pond a fan favorite during Matt Smith's run on Doctor Who is much more true to her nature than Nebula -- a brooding, masochistic, revenge-bent assassin.

And when we last left her in Guardians of the Galaxy, she'd just done some dark stuff.

"She cut her own hand off, jumped onto a ship, and flew away," Marvel Studios head Kevin Feige said, failing to mention the part about how she was trying to murder her sister. "She comes back into the story relatively early on."

Feige filled in a few details: Nebula has been captured by a superior race called the Sovereign, who are willing to turn her over to the Guardians -- but in return, they must destroy a giant space monster that is ravaging their power supply.

"[The Guardians] want to take Nebula back to Zandar, to have her, to have her arrested," Feige said. "Things go awry on that journey, and she becomes a much bigger player in the film than she was in the first one ... you explore that dynamic between them as sisters. It’s sort of Nebula’s deciding does she want to kill Gamora or is she going to set aside this internal rage?"

Gillan sat down with a small press corps during out visit to talk about her role -- a discussion flecked with hints about where Guardians of the Galaxy Vol. 2may be taking us.

So can you tell us where your character is at this point? When we last saw her, she had chopped her hand off ...Yeah, so she's on a mission to sort of rectify that because she's missing a hand. And she's also on a mission to find Gamora and rectify a few things there as well and we're going to find out a lot about their backstory and learn a lot about Thanos' parenting skills and maybe how dysfunctional the entire thing is.

Kevin Feige said we can empathize more with Nebula this time around.I think so. When you understand anyone's motivations for anything, I think you can empathize with them and that's exactly the case with Nebula here. And that's what I'm really excited about as an actress, because I want to empathize with my characters. And yeah, I think people might even feel a little bit sorry for her, if it's possible.

Do you think, like I think a lot of people liked her as a villain, but do you think they'll like her more as a hero this time around?Her default is 'very pissed off' and that's not going to change.

Thanos isn't in this movie.No.

But we learn more about him through you.Yeah, I guess so. We learn a lot about their backstory actually and what happened to these two girls growing up and actually how awful it was for them and how it's ruined their relationship and they're sort of going to freely talk about it, which has never happened between these two people.

Are there flashbacks? Like with younger versions of your characters?No. Although that would be cool. ... No, they just sort of talk about it. And when they have a conversation, it's not like two normal sisters having a conversation, it's both a conversation with words and also physically. That's how they communicate through fighting, so there's a lot of that as well.

How does Nebula get along with the rest of the Guardians that we know besides her sister? How does she kind of interact with Groot or Rocket or Peter?There's definitely some interaction between all of them. I think her main focus is Gamora. Sorting out that situation. But she finds herself with all of them and I think she is unimpressed by Rocket. She's like, she doesn't know what he is as an animal. Like she doesn't understand him.

How much will we see her interacting with new characters like Mantis?We're going to see a fair bit of that. Yeah. Mantis is a great character by the way. It's so good. ... I just think she's a really cool addition to the cast. Really different from everybody else. Even her voice is just brilliant and Pom, the actress is doing a really great job with that whole thing.

We heard that she's like a bit awkward, so how does Nebula react to Mantis?I think that she doesn't have any sympathy what so ever for her lack of social skills. Nebula doesn't have time for that. She's a sadist, she doesn't care.

Have you gotten to work at all with Kurt [Russell] while you're on set?All I want to do is watch him work, and I have watched him work. And it's like just getting a lesson on how to act basically. It's really cool, it's sort of unbelievable actually. I'm just like, "What's happening?" We get this whole thing, and he's amazing and his character is going to be brilliant and he's just really charming.

So if we're going to be getting more understanding of Nebula, and getting more empathy for her, are we also going to still see her as a badass?I think that probably I'd describe it as that you might love to hate her. She definitely doesn't cross over to the good side completely because where's the fun in that. But we will understand, we might feel sorry for, and she might, you know, this hard exterior, we're going to chip away at that and we're going to see the cracks in her sort of whole façade.

Do you push to do your own stunts?No. And I'll tell you why. It's fun, but we have a stunt girl, who's just better at it then me. Like she makes the character look cooler. Like I really think this is a joint effort on this character. I'll deliver the words and she can just make her look physically cool.

The concept art we saw shows Nebula as a full member of the Guardians.I sort of never realized that the part would go this far to be honest. When I did the first film they told me it was going to be eight days of filming and I was like, "Great." And then it turned into 18 days and in the next one and I'm like, "This is amazing. What a brilliant thing that's happened." Yeah.

Did you get to keep your hair this time?Half of it. I'm half bald under here. So from here to here it's shaved and then the top is, you know, I have hair. So we met in the middle.

How does Nebula's hand evolve throughout the film? Because we saw some artwork, sort of like a little metal claw.So one of her other missions is to sort of fix her hand as well. That's a whole other thing and it's quite funny because I've been acting like this [waves hand] for half of the time. Yeah, so she at some point makes a deal with someone to sort of fix that. Might be linked to this costume.

Someone like Taserface?Oh. Maybe Taserface is involved, maybe. I'm not committing to this mysterious hand spoiler that no one will care about.

The Guardians feel like a family now, something you're a part of. On set is it the same thing?Absolutely, yeah. It really is. I mean it was such a good experience on the first film, and I'm not just saying that because I'm sitting in front of press people, but it's true. And it's exactly the same on this one. It's really, it's just like a fun thing to work on. Some people think when you work on these bigger films, like some of the creativity is lost and stuff because you're shooting action sequences for days, but honestly that's not the case on this film. It's so creative. James [Gunn] is so loose and free when he directs us and he plays the Vol. 2mixtape throughout the scenes, which is so much fun.

What's your favorite song from the mixtape?I'm not going to tell you any songs! You sneak.

Does that help you though, in the scene? To hear the music out loud?Oh, 100%. Yeah, and it sort of unifies all of us as well. When it's big group shots or people walking, he blasts the music and it really effects everybody and their performances. But that is true of any film I think.

Gamora obviously broke away from Thanos, where does Nebula stand with him now? Does she still want his love or does she want something else?I would describe it as a bit of an abusive relationship, where you know you should be away from that person, but you for some reason are drawn to them. But she is pretty angry about the entire thing. Like she doesn't smile about it for sure.

How do you think this movie is going to surprise fans who loved the first one?It's going to be so much funnier. It's got an even better soundtrack, if that's possible and we're going to learn so much more about these characters and we're going to care about them even more. I mean the last film was establishing everything so now we have this opportunity to really play around with it all and have fun with it.