"Forever Evil" put the villains of DC Comics -- most notably Lex Luthor -- front and center, so it's fitting that writer and DC Entertainment chief creative officer Geoff Johns spent much of his Q&A Tuesday night in Los Angeles expressing his affection for the publisher's antagonists.

"I love villains," Johns told fans before a signing at a Barnes & Noble, celebrating the recently released hardcover edition of "Forever Evil." "If people know my work, they know I really enjoy writing villains as much as I like writing heroes. Lex Luthor is the ultimate villain. When I started 'Justice League,' I wanted to start with Superman, Batman and Wonder Woman, Flash -- all the characters that we know are the team -- but eventually, once that was established, I wanted to put Lex Luthor in the book. Because I thought, 'This would really mess everybody up.'"

As readers now know, the Johns-written, David Finch-illustrated "Forever Evil" -- which ran from September 2013 to May 2014 -- did indeed end with Lex Luthor as part of the Justice League, following several surprisingly heroic acts.

"It's a long road for us to get to a scenario where it's believable that Lex Luthor could be on the Justice League, but I think we earned it," Johns told the event's moderator, IGN comics editor Joshua Yehl. "The biggest thing out of 'Forever Evil' is Lex Luthor having a chance at redemption. He kind of got addicted when everyone's like, 'Oh, you saved the world, you're greater than Superman.' 'I want to do that again.'" a Lex Luthor story," Johns explained his goal of presenting new, more vulnerable sides of the long-running villain, who has plagued Superman -- across a variety of media, adaptations and continuity restarts -- for nearly 75 years.

"I wanted to see Lex Luthor care about somebody, which we did," the writer said. "I wanted to see Lex Luthor get very angry, which we saw. I wanted him to make jokes. I wanted him to laugh. I wanted him to feel guilty -- have you ever seen Luthor feel guilty? Have you ever seen him mad because somebody else got hurt?"

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Moving forward in "Justice League," Luthor's presence is poised to actually have a positive impact on the cast as a whole, Johns said, since the rest of the team, formerly marked by in-fighting, now shares a common bond: Distrust of Lex Luthor.

"Luthor's really the thing that unites them, because they all think he's a dick," Johns said. "Everybody is galvanized to become a better team, because they know they have Luthor there. They have a snake in their midst. They're all talking about, 'How do we deal with this? What's the best approach?'"

Not that Luthor is going to necessarily make life easy on his new teammates -- the series next arc, starting in October, will detail the type of effect his presence has on the rest of the group.

"We have a storyline called the 'Amazo Virus' next," Johns said. "It really explores the idea that Luthor is trying to turn over a new leaf, and he thinks he can just forget about the past. But there are some things in the past that he can't just ignore, and they come back to haunt him and blow up in his face. Someone's out to kill him. In the wake of this, something gets out of LexCorp -- the Amazo Virus. What it does to metahumans and humans is explored, and the Justice League's got to help him clean up his mess."

Lex Luthor isn't the only new Justice League member with a thoroughly checkered past as Captain Cold, the most prominent of The Flash's "Rogues," is also now a part of the squad. The character has been closely associated with Johns dating back to the writer's run on "The Flash" more than a decade ago, and he even appears -- as illustrated by Brian Bolland on the cover of 2002's "The Flash" #182 -- on Johns' door at DC's offices in Burbank.

"It's a great litmus test," Johns joked. "It's kind of cool to like comics right now, so anybody who walks in and says, 'Hey, Mr. Freeze!' I can tell them to get out of my office."

"It was the very first issue I ever wrote that was just a villain issue," Johns said of "The Flash" #182. "I wrote that in like a day in a half, only because I had thought about it for years and years and years. I find something so interesting about Captain Cold -- he doesn't want to rule the world, he doesn't want to kill people, he just kind of wants to do his thing and go home and eat dinner and watch 'Survivor,' or whatever."

For Johns, Captain Cold represents something bigger than freeze gun-assisted bank heists: the "untapped potential" he sees in every DC character.

"At first blush, you're like, 'He's a guy in a parka. He's the goofiest supervillain in the DC Comics library,'" Johns said. "I love taking characters that people have written off. I think every single character can become something very, very special if you take the time to crack into them. It's not specifically Captain Cold, it's what he represents to me for the whole DC Universe. Even Superman and Batman still have unlocked potential."

Two more villains that played significant roles in "Forever Evil" were Sinestro and Black Adam, both characters that Johns had also written previously. Despite some outward differences -- one a fallen former Green Lantern from the alien planet Korugar, one an ancient warrior antihero from the fictional North African country of Kahndaq -- Johns said the two made a natural pair.

"When these two connect -- Sinestro's all about protecting Korugar, his people. He understands the responsibility that Black Adam took upon himself," Johns said. "In a weird way, they actually get along. To have those two bond over their own feeling of, 'Only I can save my people,' we had some fun with that."

Asked which villain was his favorite, Johns, unsurprisingly, said it wasn't an easy question to answer. "It all depends who I'm writing," he said. "Sinestro's the one I spent the most time with, probably. I think Captain Cold is always going to have a place in my heart."

During the audience Q&A portion of the event, Johns shared his enthusiasm for the arrival of new "Justice League" series artist Jason Fabok, who is coming to the book after spending the last few years on multiple Batman titles.

"I'm extremely conscious of who I work with, and I'm very particular -- you want to work with the best, because it's 50/50," Johns said, talking enthusiastically of his collaborations with artists like Gary Frank, Scott Kolins and John Romita Jr. "When the opportunity was there to find a new penciler for 'Justice League,' I talked to my editor Brian Cunningham quite a bit. I looked at everybody. I saw Jason's stuff, and I said, 'Oh, my God -- he draws an amazing Wonder Woman. And he draws an amazing Batman. I wonder if he can draw Superman, and Flash, and everybody else.' I got really inspired. I said, 'This would be an opportunity for me to develop another working relationship.'

"He's already turned in his first issue, and it's absolutely beautiful," Johns continued. "I can't wait for people to see it, because I don't know if a lot of people know who Jason is yet, and they're going to, now."

Johns also addressed a fan who said he was "feeling like he was missing something" by not really understanding the appeal of "Green Lantern" as a concept. Of course, given Johns' track record of writing the character for nearly a decade, he had some passionate thoughts on the subject.

"Fear is such an anchor on everybody," "To explore a superhero that just takes fear and obliterates it, and then is inspired by other people that do it -- for me, that's really interesting, because I have my own fears, and I have my own inhibitions. Sitting up here and talking to a bunch of people is a little scary. But you kind of just have to do it. All of us, the fact that we go out of bed and we go do stuff -- we're overcoming fear to some extent to even go outside the house."

Other topics explored in the fan Q&A: The chance of a new "Legion of Super-Heroes" comic book series ("they're always talking about it," though he said it was more of a question for DC co-publishers Dan DiDio and Jim Lee), making Aquaman -- a character he said he feels like he has "unfinished business" with -- "badass" ("Who can't relate to people saying things about you that you don't want to hear? And who can't relate to somebody who's strong enough to let it go and not care about it?"), the prospects for a live-action "Green Lantern" reboot ("There's always talk of everything, I can't talk about anything else") and the chance of Lex Luthor showing up in the Johns-written "Superman" series ("I think at some point Lex will definitely come into the book").