Brian Truitt

USA TODAY

One supervillain isn't always enough. Sometimes you need a squad of them.

The Suicide Squad, DC Comics' infamous group of bad guys popularized in the 1980s, makes its first onscreen appearance on CW's Arrow Wednesday (8 ET/PT) and continues the superhero show's run of bringing characters from the comic-book page to TV, though not always in a way that fans might expect.

When it comes to springing them on the viewers, "we have the luxury of waiting til the time is right and we have the right story and the right actor and just the right moment," says executive producer (and comics writer) Marc Guggenheim.

The second season of Arrow has pitted its hooded vigilante hero Oliver Queen (Stephen Amell) against his ultimate frenemy, the dangerous Slade Wilson (Manu Bennett), but the new episode turns the focus — in the past and present — to one of Oliver's good-guy confidantes, John Diggle (David Ramsey).

He's recruited by his ex-wife Lyla Michaels (Audrey Marie Anderson) for a mission connected to a man he saved years earlier in Afghanistan during a special-forces operation. Diggle's team: A bunch of powerful convicts formed by one of the power players in A.R.G.U.S., the notorious Amanda Waller (Cynthia Addai-Robinson).

There was no grand plan for a Suicide Squad-centric story line; it came about organically, Guggenheim says, much like the team in Marvel's The Avengers movie. In the course of Arrow's villain-of-the-week episodes, the show had already introduced enough folks to put together a squad consisting of explosives expert Shrapnel (Sean Maher); clawed martial-arts master Bronze Tiger (Michael Jai White); and assassin Deadshot (Michael Rowe), the man who killed Diggle's brother.

"Obviously all these characters facilitate the creation and the exploration of the hero. All of the stories lead back to Oliver," Ramsey says. "What's been most impressive is making these other characters interesting but also still connecting them to Oliver without being heavy-handed."

Waller has long been the woman at the heart of the Suicide Squad in the comics — a team of expendable individuals put together for particularly nasty scenarios, usually by shady corners of the government. If they survive, they get time taken off their sentence. If they die, well, no biggie.

Waller has been portrayed many ways in comics and also on screen, in the movie Green Lantern and on the Superman-centric Smallville TV series. For her take on "The Wall," though, Addai-Robinson wanted to portray her as an efficient woman who could be ultimately a hero or villain.

"She's pretty no-nonsense and straight to business," she says. "There's a stillness in that — she's just one of those characters where she looks at you and you basically know what she's thinking. It's been fun to practice my looks to characters I'm interacting with."

Whether it's members of the Suicide Squad, or more heroic DC characters such as Black Canary (Caity Lotz) and Roy Harper (Colton Haynes) borrowed from the comics, several factors determine whether Arrow can pull them off, Guggenheim says.

Finding the best actor is always challenging, but so are costumes and props.

For example, two iconic aspects of Deadshot from the comics are his eyepiece and the villain's wrist guns. When he was introduced in the third episode last season, they were three times larger than they should have been for Rowe. Now, Guggenheim says, his weaponry's evolved to where it looks much better on screen.

And while he didn't come from the comics originally, Diggle's been such a hit on screen that he's now a part of the DC Universe as well in Arrow tie-in series. It's a testament to how one of the show's original characters resonated with viewers, Ramsey says.

"He's just the regular dude who has this extraordinary responsibility thrust upon him, and really that he's taken upon himself."

As much as Arrow producers love to subvert comic-book fans' expectations, they also enjoy acknowledging that lore and introducing it to the uninitiated. Wednesday's episode has an "Easter egg" related to '80s Suicide Squad writer John Ostrander, plus a blockbuster of a cameo.

"The comic book fans (in) the audience will lose their mind," Guggenheim says.

"We get a chance to bring these characters to life out of the pages of the comic and onto the screen, but the nature of the show requires us to do it in a way that's unique and original and hopefully unexpected."