John Constantine could be in trouble.

The self-professed Master of the Dark Arts can hold his own against demons and hellish threats, but television ratings may spell his doom. Despite building a loyal fanbase and providing viewers with a compelling lead, the series about the magical anti-hero and his supernatural exploits hasn't pulled in the type of numbers that guarantee it a second season. And so, with only three episodes left in its first season -- and possibly forever -- the NBC show's writers aren't holding anything back.

RELATED: Matt Ryan on Bringing Antihero "Constantine" To Life, Expanding DC's TV Mythology

Executive producer Daniel Cerone spoke with CBR News about what is yet to come on NBC's "Constantine," including the series' take on Eclipso's black diamond, the return of Jim Corrigan and Papa Midnite, wrapping up Zed's story and more. Cerone also discusses his hopes for being able to return to deal with the question of Doctor Fate's helmet, and the show's abandoned plans to adapt the iconic "Dangerous Habits" storyline from "Hellblazer." Plus, he weighs in with his opinion on whether Guillermo del Toro should be eying Matt Ryan to bring the antihero mage to the big screen in "Justice League Dark" -- strictly from a fan's viewpoint, of course.

CBR News: As you're heading into the home stretch for "Constantine," how happy have you been with what you accomplished in its first, truncated season?

Daniel Cerone: We're really happy with what the show has grown into. In the first three or four episodes, we were trying to find a tone for the show that worked for us, that honored the source material, and that also made our studio and network partners happy. Whenever you have all those different parties to address, it sometimes takes time to find the right balance. Three or four episodes in, when we feel like we hit our stride -- from there, we've just been having a blast.

Our biggest challenge is that we had a full 22-episode season mapped out on the board in the writers' room. When we got the word that there would not be an official back nine, that our first season would end at 13, we definitely had to jump in and say, "Alright -- what can we move around?" We knew what we wanted to reveal, dramatically, so we found a way to pull some of those reveals earlier.

How challenging was it, weaving in characters and story points from the "Hellblazer" comic books?

It hasn't been challenging. We had such an embarrassment of riches with those comic books. I'm literally just leaving playback right now for episode 12. We utilize a black diamond which has an iconic mythology around that in the DC Universe. We did our version of [Eclipso's] black diamond. Yes, we use the mythology as an inspiration for that episode. It's fun.

Some writers lean more into the comics than others. Cameron Welsh wrote episode 4, which was the hunger demon episode, and was straight from early "Hellblazer." He wrote our season finale also. One of the storylines from that comes from "The Family Man," which is also early "Hellblazer." For the most part, most of us were fans of the comics prior to joining the writing staff. To be able to take something that you naturally love and play around with it is a dream come true for a writer.

Initially, the series received some flack about Constantine not smoking, but he had a cigarette in hand fairly early on. Was that always the plan or the result from feedback?

It was always our intention to be true to the character as a smoker. Also, eventually we wanted to play the repercussions of that smoking as the comic did so brilliantly with "Dangerous Habits." That's definitely an arc we'd like to tackle if we have the opportunity.

The initial plan was to open a scene with him stubbing out a cigarette or maybe you end a scene with him lighting up. With every episode, we get looser and looser. If you went through and watched all the episodes, you can almost track the progression. Two or three episodes in, Constantine has a cigarette in his hand, but he's not smoking it. In the next episode, we come into scene and he's got a cigarette hanging out of his mouth for his first few lines. He's not puffing or inhaling, but it's hanging out of his mouth. The deeper we get into it, the less of an issue it becomes. Again, he's not puffing deeply through every scene, but a cigarette in his hand, or cigarette in his mouth, is commonplace on our show now.

Zed's crazy family history has been touched on. How much of her story will be resolved in the final three episodes?

We had planned to dig much deeper into that when we had the full season to do so. That arc kind of closes itself off in episode 11. We couldn't pursue it past 11. We just didn't have the geography. We draw on the fact Zed has this unhealthy relationship with her father. That is a storyline we fully intend to honor. When we brought Zed in, it was with the full intention to play out that storyline that we see early in "Hellblazer," where she's still the Chosen One, and she's still wanted by that religious faction to be their Virgin Mary or whatever it is they want with her.

For an angel, Manny has a bit of an attitude. What are we going to learn about him and his role in the bigger picture?

John is a bit of a dick, too. We like that relationship between them, because Manny gives as good as he gets, as does John. When we came up with this concept of having a mysterious angel in John's life, with his own agenda, we knew that couldn't be a soft character. We also didn't want it to be a real heavy. We wanted to make him interesting. We wanted him to have some soul and some compassion. At first, he definitely comes in and he's tough with John and he challenges him.

Again, I'm leaving playback for episode 12. Matt Ryan came and we were both watching it together. We were just laughing the whole time. That might be our most lighthearted episode, and it's all because of the Manny arc.

Basically, John gets a little sick and tired of Manny being a dick, of flying in and out, and not really helping out. John performs some magic that grounds Manny in the mortal body of a doctor. Manny is on a seat at John's side pretty much for the whole episode. He just has a hysterical arc. It's great to see Harold Perrineau's colors come out and to see his range. And heading into episode 13, there will be some revelations.

"A Whole World Out There" sees the return of Ritchie Simpson. What's he been up to?

Ritchie Simpson has been living in fear. He's very true to when we met him in the pilot. He's really given into that fear and he's slowly been disappearing from society. The whole idea of Ritchie disappearing into a computer, as he does in "Hellblazer," was the inspiration for episode 11.

On your earlier question of using source material, we definitely tackle that in our own way. It inspired our own storyline. Ritchie is basically looking for an escape plan. He knows the Darkness is coming, that there's an apocalypse coming, or at least he feels it. He's creating his escape plan, and that that's kind of the genesis of that episode.

"Waiting for the Man" is the season finale. How epic do things get?

We turn over some pretty big cards. Just being candid, it was a bit of a retrofit. There were some things we were building towards, but we wanted to leave our fans with a fulfilling season and really set them up for everything we want to do. This episode does that. It was nice that it was so heavily influenced by a "Hellblazer" issue. It also brings back Jim Corrigan and Papa Midnite. It was a great opportunity to bring several storylines to a head.

There are so many incarnations of Corrigan and the Spectre in the comics. How do you approach a character that has often been portrayed as one of the most powerful beings in the DC Universe?

Well, that's the rub. We love being part of the origin story of Jim Corrigan and the Spectre. At what point we would actually turn him, we're not even sure. Once he's turned, you definitely have a character that has been portrayed as essentially being all-powerful and unstoppable. There's not always a lot of dramatic potential in that.

Right now, we're just enjoying setting up his character. We're enjoying this secret that we know about him. As revealed through Zed, she has visions that Corrigan is going to die. She has to figure out what it means. If there are more seasons of the show, there definitely will be a destination. At that time, we'll figure out how powerful we'll make him. Like any character, he won't be instantly formed. Even if we do turn him, it will be a continuing journey to figure out what he is and how much power he has.

Ratings were up last week. Are you feeling good about the possibility of a second season?

I can't speculate. All I can say is, I continue to be humbled by NBC's continuing belief in the show. We're a little surprised ratings haven't been as strong as we would have liked, and they would have liked, yet they are sticking with us. You just have to look at the list of shows that have been cancelled. If the ratings start dropping, they essentially pull it and put reruns of "Shark Tank." I'm not joking. The fact that NBC is staying with us, and are excited about us, and still talking about another season is all we can ask for. After that, it's up to viewers, and us attracting viewers.

It's hard. It's a frustrating experience because we all live tweet. Half the time, we're all together doing it. We have such an incredible media presence and we're such a heavily streamed show. The fanbase is out there, they are just not watching in the manner that is as financially rewarding to a major broadcast network. That's the biggest frustration for us and NBC. We'll see where we end up at the end of the season.

Hypothetically, if there is another season, where would you like to see it go?

The most honest way to answer that is, we'd like the show to go deeper into John Constantine. That's what we like to write the most. I think we received some justifiable criticism in the beginning, that we were bit episodic, a bit monster-of-the-week. As we got into the season, we were able to introduce characters and be able to start character and story arcs, and moved towards living more in the world of John Constantine. That's what the show is. That's what the comic book is. That's what people signed on for. Our goal is to really explore the character.

We never did get a Doctor Fate episode.

Yeah, we had a good Doctor Fate storyline that we would still use, that there is still plenty of room for. We were utilizing the helmet -- there wasn't a Fate appearance planned in that episode. We had a big storyline built around the helmet. We've all been playing around with, "Okay, what does the helmet do and how do we use it?" Once we shot the pilot, it would have been wrong to show it and not use it. It was always our intention to play it off by the end of the season.

Lastly, any thoughts on Guillermo del Toro making Constantine a central figure in his "Justice League Dark" movie? Would you like to see Matt Ryan up on the big screen?

I would have to answer that question purely as a fan. They are not coming to us. We don't have any inside information. I'm sure Guillermo would do whatever he'd like to do. Obviously, we'd love to see Matt Ryan as Constantine. He's been widely praised. If you look at the feedback for the show, it's generally been positive, but I haven't seen anyone who has ever taken to task Matt's portrayal of Constantine. We bought a lot of early credit on the fact that we were presenting a real and honest Constantine. The bottom line is, it would be great to see him in that role.

"Constantine" airs Fridays at 9 PM on NBC.