'Arrow': Breaking Down the Last Villain Twist in "The Devil's Greatest Trick"

There was a huge status chance when it comes to the Big Bad this season on Arrow tonight, so big that Star City might find itself wishing for bad guys with bombs by the time it's all over.

Spoilers for tonight's episode of Arrow, "The Devil's Greatest Trick", below.

Cayden James (Michael Emerson) is dead. In tonight's episode, Team Arrow was able to thwart the mastermind's plan to blow up Central City and even managed to arrest the super hacker to bring him to a more traditional standard of justice. However, it turns out that Cayden was never really the mastermind or Big Bad. Cayden may have had his team of villains, but at least one of those villains never served him and was instead there for their own gain, playing an incredibly long game to get there.

While we have previously speculated that perhaps setting Cayden up to be the Big Bad this season by killing his son and framing Green Arrow for it was part of a brilliant, if not diabolical, plan by last season's villain Adrian Chase/Prometheus, we were only partially right. Yes, it was a brilliant if not diabolical plan. But it wasn't Adrian Chase -- it was Ricardo Diaz (Kirk Acevedo). In the final moments of "The Devil's Greatest Trick", Diaz visits Cayden while in custody and reveals that he didn't want to blow up the city. He wanted to set it up to take over, and that included setting up Oliver Queen both with the FBI as the Green Arrow as well as with Cayden with the murder of his son. Diaz also admitted that he was responsible for Cayden's son's death, has the new police captain and some city officials on his payroll, and -- just for good measure -- murdered Cayden.

But now that Cayden is dead, and the real villain of the season has been revealed, what is Diaz's plans for Star City? We already know that whatever Diaz -- which is a play on the DC Comics villain Richard Dragon -- it's always involved wanting to take over Star City in a sense. When Acevedo was first cast in the role last year, the character description described him as being "bent on taking over Star City's criminal underground" as well as "yet to meet a foe he can't take down."

Executive producer Marc Guggenheim even told ComicBook.com well ahead of this season that Diaz would be the Big Bad, but that he'd be more lowkey about it.

"You know, what I really like about our interpretation of Richard is, he's very grounded," executive producer Marc Guggenheim told ComicBook.com last summer. "He's not a flamboyant big bad, he doesn't wear a costume, he really is a crime lord sort of in the Tobias Church model. For Tobias we only really saw him for about five episodes, so we were excited about the prospect of doing a cool, gritty crime lord, but for a longer period of time. We've never really done that on the show before, so it's different."

In comics, Richard Diaz is alias of The New 52's version of Dragon, the son of a drug kingpin killed by John Diggle while he was Green Arrow. This recent comics history is interesting considering Diggle's (John Ramsey) turn as Green Arrow briefly earlier this season. It's possible that Arrow will bring elements of that storyline as we watch Diaz's master plan for Star City play out, even if it doesn't end well for Diaz.

Arrow airs Thursdays at 9/8c on The CW.