Supergirl's Katie McGrath Explains Why Lena Is So Guilt-Stricken Over Kara

Supergirl's Lena Luthor has had a lot on her plate. Katie McGrath's Arrowverse character remains wracked with guilt and self-blame since her brother, Lex Luthor (Jon Cryer), sent Kara Zor-El (Melissa Benoist) on a one-way portal ticket to the fractured Phantom Zone in the Season 6 premiere. She also failed in her quest to help National City's district attorney's office bring her brother down by giving testimony against him. Then, there was the whole children's hospital donation that went awry when Lex had his thugs set fire to the medical facility.

Things, though, are starting to look a little less bleak. Lena has managed to extricate herself from Luthor Corp. and cut ties with her villainous older brother. And that should mean more time with the Super Friends, who recently found themselves with a multiplying Phantom problem after one of those tormenting creatures hitched a ride inside of Silas during the group's first attempt at rescuing Supergirl.

Lena may not want to go on the record for an interview with CatCo, but McGrath spoke with TV Guide about her character's major split from the Luthor family ahead of Tuesday's new episode – "Supergirl Finds a Way Home" on The CW. We also got the scoop on how Lena is handling Kara being gone, the Phantom invasion, working with the Super Friends, and turning to Kara's sister – Alex Danvers (Chyler Leigh) for support.

Supergirl's Season Premiere Cliffhanger Will Challenge the Super Friends Like Never Before

In the last episode, Lena was really taking her power back. What did you think when you read that script? It's a really big change for your character.
Katie McGrath: You always sort of do a debrief with [the showrunners at the end of the season about] and what the character is and where they're thinking of going, and the one thing that I sort of said to them that was really important for me, for Lena, was I'd really love to see her finally start to be okay with who she is, and accept who she is – good parts and bad parts. And sort of forgive herself, but also not let herself get away with things. And I think that's kind of where they're taking her this year, which is so lovely to see. And it's such a...very grown-up way of looking at things. It's very adult, it's very grounded, which for me is great and I'm really enjoying it. I'm really thankful that they sort of agreed with that idea.

The line that she had to Lex – she loves herself more [than she hates him] – what a powerful moment.
McGrath: I know.

He didn't quite know what to make of it. Do you have anything you can tell us about how he's going to interact with her going forward or how she's going to interact with him? 
McGrath: Obviously she doesn't want him in her life, you're completely right, but he is, in fact, her brother and he is sort of this personification of evil in her life that is in fact also part of her. So for all that she's like, "I don't want you part of [my] life," I don't think she can ever realty truly let him go yet. I don't think you've seen the last of that relationship. She has taken her power and she has walked away, but I don't believe it's done yet. I think there's more to come. But I think Lena, at the start of Season 6, is setting herself up to be in a really good position to be able to deal with the rest of it, whatever that may be.

Let's talk about Kara, who's been in the Phantom Zone since the opening of the season. Kara and Lena had just started to repair things between the two of them. That has to be weighing on Lena that they could never see each other again.
McGrath: And not only could they never see each other again, but also, Lena feels responsible for putting her there. So, this woman is her best friend, and all of a sudden she's faced with the idea that she will never come back. "It's my fault." What does that mean for our friendship? But also, what does that mean for the world, you know? This is the hero that is consistently saving the planet and I have banished her to this place and she's not going to be able to come back and I feel responsible. So much of what Lena's dealing with right now is feeling responsible and feeling not good enough and feeling like everything's her fault and trying to accept that everybody makes mistakes and making a mistake doesn't make you a villain. And I think that's where she's sort of at the minute is trying to accept that she can be forgiven and that she can move on and that she can still be a good person even though she made a mistake.

According to this episode's logline, things aren't going to go so well with the Super Friends and deciding how to deal with the Phantoms that are infecting people and multiplying in National City. That's got to hurt her confidence, I would imagine.
McGrath: For sure, because again, she feels responsible for this. This is all coming from a point where she's like, all of this -- this little thing that I did or didn't do has now just spiraled into this, and look at the mess I've made. ...I feel like Lena's sort of constantly sitting there going, "Look at the mess I made, and I was only trying to do good." She knows she did wrong, but it wasn't from malice. She wasn't trying to hurt anybody. She was trying to help, and it was obviously taken and twisted. Lena has like the most…overdeveloped conscience. She's very Irish in that. Guilt is way up there as her overriding feeling at most times. So, Season 6 -- so much of that is her coming to terms with again, like I said, trying to learn -- and Alex helps her a lot in this – is trying to learn that it's okay to make a mistake and that doesn't make you a villain as long as you try and fix it. There's some lovely stuff in the episode coming up between her and Alex where Alex sort of helps her see that.

Alex was the first one to have trouble when they couldn't get Kara back right away, then she helped J'onn J'onzz. She's essentially being the sister to everyone, I guess.
McGrath: Yeah, that's a really good way of putting it, actually. Yeah, she is. She's kind of being the pin in the middle and helping us all.

The CW Sets Spring Returns for Legends of Tomorrow, Charmed, and More

It is interesting though because everyone's going through their own journey with Kara being gone. Are they all going to eventually turn to each other and realize they can all support each other and brainstorm and hug each other and cry it out and do whatever they need to do?
McGrath: I think one of the great things about Supergirl as a TV series is we have our hero, but we also have a team that works very well together, and when it comes to this specific issue, and a lot of issues – not just this one – we realize that we are all stronger together, and we rely on other people's strengths to cover our weaknesses, and our strengths will cover theirs. And I think that's a really good metaphor for how the sort of team of Super Friends work is that … they can fix it together. And I think that's what's so hard about not having Kara, is because she's such a huge part of the team. She is the leader and the Beacon of Hope. Without her, the team doesn't feel like it can function and it's learning to function without her.

What do you want most for Lena by the end of the season?
McGrath: I'd like Lena to be fully happy with who she is, to be fully [accepting] of herself, to be fully at ease with who she is, who she was, and who she's going to be. That's my hope for her.

Obviously, it being the last season, what are you going to miss most about being on Supergirl? 
McGrath: I'm going to miss playing with my friends, you know what I mean? Like, as a person. I'm going to miss going to work with my friends and there are some days where it's so silly, but it's still so cool. I mean ... what else are you doing, you know, you're fighting a giant alien. Everyone's in a super-suit. You're like, "How is this my life?"...I'm from a small town in Ireland and [the show is] all flying and shooting lasers. I mean, it's fun, and I'm going to miss that. There's such a suspension of disbelief of doing these sort of massive science-fiction fantasy shows that it so takes you out of your real life, and I'm going to miss that.

That's something I never even thought of before. Yeah, because most things are drama, human stuff.
McGrath: Yeah. And this show does have all of those bits – 100 percent, but the days that I will miss are when we're all there and we're doing something that seems ridiculous but is so much fun, and you're like, "How is this my job!? How do I get paid for this!?"

Do you have a particular memory of something you did on one of the episodes of the show that you still can't get over?
McGrath: This is the first time I've been part of the Super Friends. I usually come in and say something sassy and do something and walk out. I did love getting to punch Jon Cryer. That was kind of epic because, you know, it's Jon Cryer. And I decked him...it was great. …She's obviously fought before, but that was just fun for me. Poor Jon.

Supergirl airs Tuesdays at 9/8c on The CW.