The last time viewers saw Stephen Amell's Oliver Queen on "Arrow" he had decided to leave Starling City to begin a new life with his girlfriend Felicity.

However, "Arrow's" executive producer revealed that the vigilante's newfound peace and happiness will be interrupted when a new big bad of "pure evil" comes to town in Season 4.

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 Merlyn 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 into the sunset with Felicity by his side. As a result, the five months that he spends in reclusion marks the first time that he experiences a degree of "normalcy," showrunner Marc Guggenheim told Access Hollywood.

However, the EP went on to say that Oliver will quickly be called back to Starling City when Season 4 premieres as he will face off with Damien Darhk.

"Damien's a different kind of villain than we've had on the show before," said Guggenheim. "He's not as centurion as Ra's, he's not as looney tune as Slade, he's not as -- and people will be surprised I use this word -- but he's not as noble as Malcolm Merlyn. He's pure evil. We wanted someone who was truly, truly malevolent. We've never done that on the show before. All of our big bads always thought they were doing... the wrong thing for the right reason. This guy does the wrong thing for the wrong reasons," he said.

The EP went on to say that viewers will be introduced to the Neal McDonough's Damien Darhk early on in the new season.

"It's a bad situation to have this guy coming in. And the other thing that we're doing that's different is in past seasons, you've had to wait 'til usually the mid-season finale to meet the big bad and have Oliver confront the big bad. We are coming out of the gate strong. We're not waiting and actually, that itself has really energized the show and it infuses even the 'villain of the week' episodes with an epic-ness that they wouldn't otherwise have."

According to The Hollywood Reporter, fans will also be introduced to the villain Baron Reiter, better known as Blitzkrieg, in Season 4. British actor Jimmy Akingbola has been cast in the recurring role and will be prominently featured in flashback scenes.

In the DC Comics, Blitzkrieg is the head of the crime organization Shadowspire. When the org appeared in episode 53, it supplied South American drug cartels with weapons, transportation, technology and intelligence, reports THR.

Other additions to the new season include Alexander Calvert as Lonnie Machin/Anarky and Echo Kellum as Mister Terrific.

J.R. Bourne has also been cast to play Jeremy Tell. Better known as Double Down, Jeremy is a metahuman that can "turn his playing card tattoos into deadly weapons," reports What Culture.

In DC comics, Jeremy is a con-artist who gained superpowers after he lost all his money in a poker game and then killed the winner. That's when the deck of cards melded with his flesh, giving him the ability to detach them and use them as weapons.

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

Watch Marc Guggenheim's interview below.