Although Constantine failed to hit the ratings metrics NBC required, the series managed to build a rather loyal fan following. within the span of a mere 13 episodes, Ryan's portrayal of the character became iconic, and viewers were quick to voice their dissatisfaction with NBC's decision to cancel the show. In fact, it was fan demand that eventually led Warner Bros. to release the complete first season of Constantine on Blu-ray and DVD two years after the series' last aired on television.
The character proved so popular that he would transcend networks. The CW's decision to bring Ryan's John Constantine -- accent, trench coat and all -- to the Arrowverse was no small miracle. It was an uncommon move that would eventually lead us to where we are now, with Ryan looking at a full-season contract on Legends. But the character isn't all that made the transition into the Arrowverse.
Constantine's appearance in the Legends of Tomorrow episode "Daddy Darhkest" made mention of the Hellblazer's failure to save a possessed girl named Astra, an event that took place on the NBC series. This would indicate that The CW has retroactively absorbed the entire first season of Constantine into its own continuity, making NBC's series an official part of the Arrowverse.
Therefore, all of the events that took place in Constantine, from John meeting Zed to his battle with the Rising Darkness, are part of the Arrowverse. What's more, these threads that were part of the character's solo series, threads that were never properly tied off, can now be addressed. Constantine's Season 1 finale left us with a shocking cliffhanger when viewers learned that John's friend and ally, an angel named Manny, was in fact working against him and was actually the one behind the Rising Darkness and a group of demonic villains known as the Brujería.
With the Legends facing more and more mystical threats in Season 3, it would make sense to see the next season virtually forgo time travel and go full-on mystical with Constantine. The threat of the Rising Darkness and the Brujería terrorizing the Arrowvrse may not be enough for a season-long arc, but it deserves some attention over a few episodes, to give both fans and the character some proper closure to those adventures. It would be a simple task to reveal the events of Constantine took place over the last season or two of Arrowverse series, allowing both timelines to sync up smoothly.
These aren't even all the threads that Constantine left us with. The series also introduced Jim Corrigan to its cast, and teased the police detective's eventual transformation into The Spectre, God's very vengeance made sentient. On top of that, the series also teased the Helmet of Fate, which was in John's possession. The idea that the Legends might come across both The Spectre and Doctor Fate in a season focused on magic is an arc that seems too good to pass up.
With Constantine coming aboard the Waverider full time, Legends of Tomorrow has everything it needs to conclude a story that was first established four years ago, all while blowing the doors wide open on the mystical side of the DC Universe. That seems like the perfect set of ingredients for a potent spell to us.
Airing Mondays at 8 p.m. ET/PT on The CW, DC’s Legends of Tomorrow stars Arthur Darvill as Rip Hunter, Dominic Purcell as Mick Rory/Heat Wave, Caity Lotz as Sara Lance/White Canary, Brandon Routh as Ray Palmer/Atom, Maisie Richardson-Sellers as Amaya Jiwe/Vixen, Nick Zano as Nate Heywood/Steel and Keiynan Lonsdale as Wally West/Kid Flash.