The first season of "Arrow" hinted that DC Comics supervillain Ra's al Ghul was a looming presence in the show's world, and the second season has brought the character to prominence. His League of Assassins has been established as training both Sara Lance (Caity Lotz) and Malcolm Merlyn (John Barrowman) and the lingering threat of Ra's has increased as the season has progressed.

Despite numerous mentions of Ra's, the character hasn't actually yet been seen on the show, and the "Arrow" creative staff won't confirm if there are any plans in place to change that in the near future. But this week's episode, "Heir to the Demon," sees the series get a whole lot closer, with the introduction of Ra's daughter -- Nyssa al Ghul, played by "Spartacus" alum Katrina Law.

"She's second to him [Ra's]," "Arrow" executive producer Andrew Kreisberg said during a press event at The CW's Burbank headquarters. "She's one of the most important figures in the League. They sent their first round of minions to come for Sara, and that didn't go so well for them, so now they're bringing out the big guns. The way Nyssa comes into the story is in a more provocative and surprising way than the last round [of League of Assassins members]."

The show's producers stated the choice to use Nyssa rather than Ra's most famous daughter was motivated by Talia recently being portrayed on screen in 2012's "The Dark Knight Rises." Nyssa -- known in the comic books as "Nyssa Raatko" -- was introduced in 2003's "Detective Comics" #783 by Greg Rucka and Klaus Janson. Unlike Ra's or Talia, this is Nyssa's first adaptation to another medium.

"I love the fact that she hasn't been in any movies, and interpretation is left wide open between the writers and myself, and what we want to do," Law told reporters. "I love that she's only been in the comic books I think a total of 19 times. Everything about her is just wide open. It's so much more fun than having something that's rigid and defined for you that you have to play with in the confines of a box."

In a sign of Law's enthusiasm, executive producer (and comic book writing veteran) Marc Guggenheim shared that Law "ended up doing a lot more stunts" for the episode than expected. Though Law had performed stunts during her time on Starz's various "Spartacus" series, she said playing the highly trained Nyssa al Ghul was a different experience.

"[Mira, Law's character on "Spartacus"] was untrained, so she could be wild, whereas this girl is precise, and everything that she does has a purpose and intent," said Law, adding that she tried to make sure to keep her movements "sharp."

Playing Nyssa al Ghul also granted Law one of the distinct fringe benefits that comes with acting in genre TV: Wearing a costume.

"As an actor, you want to play," Law said. "The first time I put the costume on, I had this moment where I just kind of geeked out in front of myself in the mirror. It was so good."


"Maya Mani is our costume designer, and every week we're like, 'Hey, can you do a costume for this incredibly iconic comic book character that feature films have years to devise?,'" Kreisberg shared. "In a week we have yet another amazing costume that you can't imagine the show without."

Ra's al Ghul is primarily known as a Batman villain, but the "Arrow" team is keenly aware there's a precedent for the villain making an impact throughout the DC Universe -- including Green Arrow's corner of it.

"DC has been really amazing about letting us open that playbook," Kreisberg said. "Although a lot of people associate Ra's al Ghul with Batman -- which is true, that's where he started -- he really encompasses a lot more than that. I think now that the Dark Knight movies are completed and that storyline has been wrapped, it's allowed us to open it, and put it through the 'Arrow' lens, and do it in a new way."

"Merlyn on our show is a member of the League of Assassins, but also Merlyn in the comic books was a member of the League of Assassins," Guggenheim pointed out to the assembled press. "The comics made this possible for us, in a way."

Nyssa and Sara's shared past with the League of Assassins makes for a natural connection between the characters, one that's explored in "Heir to the Demon." For Kreisberg, it made for an especially meaningful villain encounter.

"I think Nyssa's one of the best characters we've ever had on the show," Kreisberg said. "Not wrongly, it's been pointed out that sometimes our villains get short-shrift. We don't always do right by the villains coming onto the show. Some of that is just because our show is so dense with so many different characters. We've gotten away with just casting very cool people in the parts, and asking the audience to fill in the rest.

"I think that's why, to me, this is one of our most successful episodes that we've ever done," he continued. "Every single aspect of it is working, not just with our main characters."

Both Kreisberg and Guggenheim stress the importance of "Heir to the Demon" to the overall "Arrow" mythology -- even if the full payoff may not be apparent for a while.

"We're always not just thinking a season ahead, but into next season," Guggenheim said. "There are little nuggets that we've actually already sprinkled throughout this season that won't pay off this year -- it'll pay off next year. You'll see, 'There really was a plan. They really did know what they were doing.'"

This week's episode of "Arrow," "Heir to the Demon," airs 8 p.m. on Wednesday, Feb. 5. on The CW.