More Details on John Constantine's Role in 'Arrow' Season 4

News broke earlier this week that Matt Ryan would guest star as John Constantine on the upcoming Season 4 of Arrow. Now, some more details about his role have been revealed and it looks like the character will have a direct connection to DC's Legends of Tomorrow.

Ryan, who played the titular character on Constantine on NBC for one season before the network canceled the show, will dust off his trench coat and step back into his shoes for a guest spot on Arrow. Executive producer Marc Guggenheim has now teased why Constantine shows up in Starling City.

Recall the trailer for Legends of Tomorrow in which we saw Sara Lance (Caity Lotz) emerge from the Lazarus Pit, the healing fountain introduced in Season 3 of Arrow that has the power to mend wounds and even bring people back to life. From the trailer, it seemed that this would be how Sara returns as White Canary, but Guggenheim hinted that there's more to it than that.

"Unlike Thea, who wasn’t fully dead, the consequences of using the pit on someone as dead as Sara was creates some unforeseen difficulties," he said, according to TV Insider. "And John Constantine is uniquely suited to help our team deal with those."

Guggenheim is referring to the later episodes of Season 3 in which Oliver agreed to become Ra's al Ghul to bring his sister back to life and she returned with amnesia.

Interestingly, the EP called Ryan's appearance a "one-time only deal." But he then went on to talk about how he fits in the fabric of the show in Season 4.

"Each year on the show, we have added and expanded the mythology with different elements. In Season 2 we introduced the idea of superpowers, last year brought in the League of Assassins, and for Season 4, we always had a plan to introduce magic and mysticism. We were already swimming in those waters and that's why Constantine is this great organic little development."

Guggenheim also expressed his enthusiasm for the crossover. "This is something the fans were clamoring for," he said. He also praised DC as "magnanimous and generous in giving us this one-time dispensation. The trench coat, the tie, the shirt...the whole wardrobe is being taken out for storage and shipped up to Vancouver."

Finally, he noted that John Badham, a director from Constantine, will helm the Arrow episode. "He is familiar with Constantine and Matt Ryan, so it’s a wonderful combination."

Are you excited to see the character show up in the Arrow world? Let us know in the comments section.