John Constantine isn't among the best-known DC heroes, at least when it comes to superhero fans who don't read comic books. When Constantine first appeared on the big screen in the 2005 movie Constantine, portrayed by Keanu Reeves, he wasn't linked to any other superheroes, making it seem like Constantine wasn't a part of the DC universe.

RELATED: Best Red Hood Comics To Read Before The Game Gotham Knights Comes Out

That changed when Matt Ryan played Constantine in the Arrowverse and joined the crew of the Legends of Tomorrow. Since a sequel to Keanu Reeves' Constantine movie is rumored to be in development, it's as good a time as any to learn more about Constantine by reading some of his comics that best introduce the character to new readers.

5 All His Engines

John Constantine All His Engines

Of all the John Constantine comic books, this one has the closest link to the 2005 movie since it was released at the time of the movie's premiere in order to bring people up to speed and explain who John Constantine was. So even though different characters appear in the comic book, the plot has a similar feeling to it. Once again, Constantine is helping a woman who's in trouble even though it means he has to take on demons who wouldn't hesitate to hurt him or worse. This time, it's the granddaughter of his friend, which makes the case even more personal for John.

Both All His Engines and the movie have a similar feeling to it of danger and darkness. It's interesting to read how John will find his way out of the trouble, and the result might surprise the readers. This storyline is a good indicator that John Constantine isn't all about spells and action but isn't afraid to use his intelligence against his enemies, which makes for a compelling read.

4 Dangerous Habits

John Constantine Dangerous Habits

If the readers saw Keanu Reeves' Constantine and want to start on familiar ground, the storyline Dangerous Habits available in Hellblazer #41-46 is a good option. Garth Ennis is an experienced writer who penned some of the darkest and best comics, and characters like Constantine and Punisher fit his style. In this story, John is fighting his terminal lung cancer...and he's losing.

RELATED: Best Black Adam DC Comics You Need To Read Before The Movie

The same thing happened in the movie in which John knew he was about to die and did his best not to go to Hell considering Satan was angry at him. Satan makes an appearance in this storyline as well, but that's where the similarities between the comic book's plot and the movie's story end. Despite that, there are enough similar points to ease new readers into the story and allow them to see what the comic book John Constantine is about.

3 Rake At The Gates Of Hell

John Constantine Rake At the Gates of Hell

Even though this storyline closes Garth Ennis' Hellblazer run and appears in Hellblazer #78-83, it's still understandable for beginner readers who haven't met the comic book version of John Constantine before. At least in case, they're familiar with his Arrowverse storyline and the fact that John failed to save the girl Astra who ended up in Hell and then returned to turn John's life into a living hell.

Rake At the Gates of Hell shows how Astra's fall and return happened in the comics, and it's interesting to compare the comic book version with the television one. Unsurprisingly, the original is even darker than what the viewers got in the Arrowverse, so even those who know Astra's Arrowverse story well will be surprised by what they learn about the character in the comics.

2 Out Of Season

John Constantine Out of Season

Another comic book storyline that happened in the Arrowverse and will therefore be understandable to all fans of Matt Ryan's John Constantine was written by Mike Carey. In both cases, John ends up without his powers and has to find a way how to deal with it. The causes for this loss are different, though. In the Arrowverse, John loses his powers after helping Astra. In Out of Season, John gives up his powers willingly (more or less).

RELATED: Best Nightwing Comics To Read Before The Game Gotham Knights Comes Out

He has a hard time moving on, not because he doesn't want to turn his life around, but because multiple people around him (and other creatures) want to make certain that John doesn't get any time to rest. So he has to take on the Beast of the Apocalypse in this story which is easily one of the biggest challenges John has faced in his life. The storyline allows the readers to dig deep into John's way of thinking, and as such, is an ideal way how to get to know the character better.

1 The First Appearance

John Constantine First Comic Book Appearance

As with all other superheroes, a good way to get into their story in the comics is to read the comic book where they appeared for the very first time. For John Constantine, this happened in Swamp Thing #37 in June 1985. Even though it's John's earliest appearance in the comics, he already has his characteristic look and other traits the readers and viewers alike grew to associate with him over the years.

Such as the fact that he's a smoker and, of course, the fact that he can do magic and knows what he's talking about when he warns about an upcoming crisis. Looking back at it, Constantine got fleshed out more as a character in the upcoming years after this comic book issue, but even so, it's a good read for anybody who wants to go all the way to John Constantine's roots.

MORE: The Best DC Comics To Read After Watching The Batman