The cast and staff behind The CW's "Arrow" unleashed a host of spoilers at Comic-Con in San Diego earlier this month, including Oliver's new costume, transformation into the Green Arrow and his newfound peace.

After an intense battle with Ra's al Ghul in the Season 3 finale, Oliver took down the leader of the League of Assassins and saved Starling City from destruction. Malcolm Merlin then stepped up as Ra's successor and became the new head of the League while Thea adopted a new superhero identity as Speedy. In addition, Oliver decided to hang up his hood to drive off in a convertible with Felicity to start a new life with her.

Fans will find Oliver and Felicity enjoying life in reclusion when Season 4 kicks off in October.

"Oliver's totally at peace at the beginning of Season 4. We see that in an emotional sense and in a body posture sense. We see it," teased Executive producer Wendy Mericle, Yahoo! News.

Mericle went on to say that the show will explore the dynamic behind Oliver and Felicity's romance.

"It's interesting who [Oliver or Felicity] is happier than the other one. Who is more at peace than the other one. It's almost always -- if you were to say 'Who's restless? Who's angst-ridden? Who's this, who's that?' -- of course it would be Oliver," said the EP.

She also hinted that the new season will include more "Oliver in a suit stories," since it will be more difficult to be the Arrow.

Meanwhile, executive producer Marc Guggenheim opened up about casting actor Neal McDonough to play the season's big bad, Damien Darhk.

"We just needed an amazing actor; someone who commanded the screen. With Matt Nable and John Barrowman and Manu Bennett, the bar is set really high. So we needed someone who could play at or above that level and in Neal, we found someone who has -- if you'll pardon the pun -- the darkness and can project that menace that we need in a great villain. It's a cliché, but it's true: Your hero is only as good as your villain," said the showrunner.

"One of the things we're doing this season which is really awesome is -- unlike previous seasons, where we waited halfway through the season in order to put our Big Bad on stage -- you're going to get Neal McDonough as Damien Darhk right from the jump," continued the EP.

Actor John Barrowman, who plays Malcolm Merlyn, revealed that his character will be "even more evil and bad--s than what he was. And also... there will be magic involved because I am The Magician."

Viewers can also expect to see Anarky, an elite criminal who is closely associated with Norm Breyfogle's time on the "Batman" titles, in the upcoming season.

According to ComicBook.com, Anarky, or Lonnie Machin, is described as a "deranged freelancing criminal who is willing to do whatever it takes to impress a potential employer. If his history with Robin is any indication, he might create a real problem for a certain young sidekick who has recently taken up the mantle of Speedy."

Furthermore, A.R.G.U.S. will continue to be a big part of the storyline involving Diggle and Lyla.

Episode 1 of Season 4, "Green Arrow," will premiere on The CW on Wednesday, Oct. 7.