SDCC: "Arrow" Cast & Crew Dish Out Details on Season 5

"Arrow" -- the show that kickstarted the FlArrow extended universe -- is back at Comic-Con International at San Diego. In anticipation of the Season 5 premiere, Wendy Mericle, Echo Kellum, Paul Blackthorne, Emily Bett Rickards, Stephen Amell, David Ramsey, Willa Holland, John Barrowman and Marc Guggenhiem stopped by to discuss the upcoming season, including the new villain, Oliver's new role as mayor and more.

"He's a new character. He's our big bad for the year. We call him Prometheus [but] it's not the Grant Morrison/Howard Porter character," Guggenhiem revealed. "He's pretty badass."

"With Laurel being gone, it's incredibly important for the team to move forward, remembering that legacy and honoring it," Mericle said. "We will definitely see [Katie] Cassidy in the season premiere." She added that Cassidy has a deal like John Barrowman and Wentworth Miller, where she appears across all of The CW's DCTV shows.

As it turns out, the 100th episode will also take place during the second episode of the four-way DCTV crossover.

"He's in Chechnya with the special forces... He's still a man of two minds. He misses the times, but he's still dealing with the tragic death of Black Canary [and] his brother," Ramsey shared. "He's still conflicted about the events of Season 4."

"I think Curtis is just really influenced by Green Arrow. He really looks up to him," Kellum revealed. "It's a struggle."

"We've got some pretty big plans for Curtis, especially in respect to his marriage. He want to become a vigilante and he wants to start fighting crime. At the same time, he's got this husband at home, who's going to notice he starts coming home with bruises and cuts," Guggenheim explained.

"Thea has gone through a lot in the last four seasons," Holland said. "She just needs to take a step back for a second and realize what's going on in her own psyche." She also hinted that she would be helping Oliver as he fulfills his mayoral duty. "This year, she's going to be doing a lot of stuff. She's going to be helping Oliver, but in a different way... He's a vigilante moonlighting as the mayor."

"All of his focus and all of his energy is going into being Green Arrow and trying to stop crime in Star City," Amell explained. "Thea is carrying all the water as mayor."

"[Merlyn] is the bad guy who's the hero of his own story, and it'll be interesting to see what he's like in these different times," Barrowman shared. "Listen, I've time traveled before. I know how it works. I'm excited as an actor to play those different things."

Asked if Bruce Wayne will ever appear on "Arrow," Guggenhiem said, "No."

"I would say 'never say never,'' Amell interjected, to which Guggenhiem said, "I would love to have Bruce on the show."

To close out the panel, a fan asked if Amell would sing them a song. He started out singing Jonathan Groff's "You'll Be Back" from "Hamilton," and soon the rest of the cast joined him.

"I will never, ever, ever do a musical episode on the show," Amell concluded.

"But we do want a musical on the show!" Barrowman pitched in, to thunderous applause.

Starring Stephen Amell, Emily Bett Rickards and David Ramsey, "Arrow" will return to The CW on Wednesday, October 5 at 8 pm EST.

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