One of the most iconic DC Comics characters to be featured in both the main DC Universe and his own Vertigo Comics title is John Constantine, the Hellblazer. Initially created as a supporting character for Swamp Thing, the occult magician and con artist's escapades were eventually relegated to their own continuity as part of DC's mature readers publishing imprint Vertigo, where the character flourished in mature-readers stories. However, the character has been softened somewhat in recent years as he has been reintegrated into the main DC Universe.
Created by Alan Moore, Stephen R. Bissette, Rick Veitch and John Totleben in 1985's The Saga of Swamp Thing #37, Constantine served as an ally to Swamp Thing and helped him realize his full, supernatural potential by introducing him to the Parliament of Trees, which presided over all plant-life on Earth. As a quick hit with readers, Constantine received his own series in 1988's Hellblazer, which was grandfathered into Vertigo's line when the imprint launched in 1993. As the longest-running single Vertigo title, Hellblazer depicted as Constantine as a foul-mouthed, chain-smoking, substance-abusing, promiscuous ne'er-do-well who was called to investigate numerous supernatural threats around the world. These cases would often result in those that grew close to Constantine meeting an untimely end or far worse as the tortured occultist lived with the full consequences of his vocation.
Shortly before the New 52 relaunch, Constantine made a limited return at the end of DC's Brightest Day event, where he investigated the reappearance of Swamp Thing. While the original Hellblazer series -- which saw Constantine age in real-time and face the limits of his own middle-age -- came to an end with its 300th issue in 2013, a decades-younger Constantine was woven more prominently back into the DCU.
This new comic book Constantine was less prone to having his companions killed off in horrible ways, indeed serving as a reluctant member of Justice League Dark alongside his on-again/off-again girlfriend Zatanna. This Constantine's only visible vices were his trademark addictions to booze and cigarettes, with the harder drugs only alluded to rather than shown outright. And while Constantine certainly had more than one romantic interest upon his return to the DCU, his promiscuity was also toned down as he teamed up with DC's more iconic superheroes on a semi-regular basis.
The other major turning point for Constantine was that Hellblazer ended the same year that Constantine's short-lived television series premiered on NBC, which brought a decidedly PG-13 version of the occult detective to wider audiences worldwide. Portrayed by Matt Ryan, the television incarnation of Constantine was less of an irascible scalawag as the original Vertigo source material in order to appease the sensibilities of network television. Despite this Constantine's softer edges, Ryan received widespread acclaim for his role, and Ryan's Constantine eventually transitioned into the Arrowverse after his own series only lasted a single season.
In 2016, Constantine even appeared in the kids cartoon Justice League Action, where his chain-smoking was reduced to an affinity for lollipops.
While that remains his only foray into all-ages programming, Constantine continues to be a more family-friendly sorcerer -- well, as family-friendly as John can get -- as he works alongside the superheroes of the DC Universe as a recalcitrant hero himself. This past year, the classic Constantine would return in the mature reader-oriented publishing line The Sandman Universe, whcih is overseen by Neil Gaiman.
In his new title, John Constantine: Hellblazer the foul-mouthed, lovably acerbic character burst back into the scene in London, where he got back to causing mayhem in pubs and at odds with modern sensibilities as he continues to ruffle feathers. And with two different versions of Constantine now being published by DC, fans can have their cake and eat it too, with both the superhero-adjacent occultist and the world-weary, harder-edged older incarnation.