Despite having a lot going for it, Constantine only had one season. It was a tale of redemption with a title character flawed enough to root for, and side characters pivotal to the plot. Tasked with saving the world from a rising darkness, Constantine rushes to do what he can, while Manny, an angel, occasionally gives guidance.
All these ingredients made for a great show. Since we only had a season one, many storylines were left unfinished: some small, some big.
10 The Prophecy Of Jim's Death
We end the series with Zed, Constantine's friend and a woman of extraordinary supernatural gifts, deciding to tell Jim that she foresaw his death. Jim had noticed that Zed couldn't look him in the face and had asked if she was all right. Telling her that she could always talk to him, he assumed that her unease was due to the intensity of the case. However, he found out it's because every time she looked at him, she saw his death. She didn't know when or where or if it could be averted.
Jim takes it in stride, says that he will live each moment to its fullest, and kisses Zed. Still, we know that Jim was supposed to die in the future. We just never saw it played out on the TV show.
9 Ritchie's Alternative World
Constantine travels with his pal, Ritchie into an alternative world created by a psychopath in order to save a student. While there, Ritchie discovers his own power and destroys the psychopath's world, creating another one that is beautiful with sun, hills, and flowers. Ritchie is tempted to stay there, but Constantine convinces him to come back. However, even if Ritchie isn't in that world, it still exists. We wonder if it would have returned in a second season, even if for a quick relax destination for our team.
8 Papa Midnite's Sister
From Constantine, we learn that Papa Midnite's sister was damned to hell with Papa Midnite playing a hand in it. Papa Midnite calls on his sister often for guidance and to learn what is going on in hell and other supernatural realms. In ceremonies, he sometimes even uses her skull to connect with her.
In the last couple of episodes, he tries to kill Constantine for a bounty. He's been told that if he brings la brujeria Constantine, they will free his sister's soul from hell. In the TV show, we don't know much of the sister's storyline, which is guaranteed to be dark and make Papa Midnite even more of a villain, especially if they borrow from the comic storyline.
7 Zed's Tumor
Towards the end of the series, we learn that Zed has a benign tumor growing in her brain. She wonders if it is the reason why she has visions, if her visions are medical, rather than magical. Manny, the angel, answers her without directly addressing the question, leading her to the conclusion that her visions are divine/magical. Still, Zed has a tumor that she decides not to get treated. The tumor wouldn't stop growing and causing her pain; however, they act like Zed is fine. If this had gone on for another season, we imagine that this storyline would have continued and been a source of agony for Zed and her friends.
6 Jasper And His Preparations
Jasper is who brings Constantine back into the fold. He has died, and he is keeping Constantine to a promise to protect his daughter. Jasper created their safe house, gathered magical tools, and kept records. He is both an actual ghost in the first episode and a figurative ghost in the rest of the episodes. His name is mentioned often; however, we know very little of his backstory and his connection with the other characters. By all means, he seems to have been as knowledgeable, if not more than Constantine. However, his storyline is left unfinished.
Speaking of being left unfinished, Jasper's daughter's story is probably one of the most unfinished of all. She is the reason that Jasper possesses someone in order to get in touch with Constantine. Also, she is the reason that Constantine gets back into the game. She has a demon after her because her powers, the same powers as her father's, are waking up. She can see the world as it is, even the ghosts and demons in it. After witnessing a tragic disaster, she runs away from Constantine and that life.
It seems unlikely that she would be able to hide or control her gift. She seemed very important to the work, and it's odd to have that storyline completely unfinished. In addition, Constantine promised to protect her. By letting her go nearly defenseless in a dark world that wants to harm her and not keeping her safe at Jasper's, Constantine didn't fulfill his promise. You'd expect the ghost of Jasper to come back and protest.
4 Invunche Demon In The Convent's Sewer
When Anne Marie (Constantine's former friend, co-practitioner of magic, and girlfriend) and Constantine are in the convent's sewer to rescue babies, they see an invunche. Constantine is even surprised it is there. Powerful and dangerous, there's no way for any human to survive it. So Constantine, evokes a powerful demon, inviting that demon to possess him. The invunche gets near, recognizes Constantine as one of its own, and leaves. However, it is still loose in the sewer. More so, why is it in the sewer under the convent in the first place?
3 Zed/Mary And The Resurrection Crusade
When Zed seeks out Constantine, she is both running towards something (understanding her visions and place in the world) and running away from something (her father and his group, the Resurrection Crusade). Her father sees her as an important to the Resurrection Crusade's work. Zed had been isolated much of her youth, and when she escaped she changed her name from Mary to Zed. She tells a potential kidnapper (one of her father's men) that she would rather be dead than go back living in isolation and with her father. We know very little about this storyline, only that Zed was afraid of her father, and that he liked that she was having visions. Also, we know that he was trying to control her, and Zed was considered someone powerful and important that could be exploited.
Astra was the young girl whose soul Constantine damned to hell. He was trying to help; all of his crew was trying to help. Astra had been possessed, and Constantine evoked a stronger demon to take down the lesser demon. It backfired. In the early episodes, it was Constantine's goal to save her soul from damnation. Astra was the reason why each of his old friends didn't keep in touch with him and why each was trying to figure out how to live in the world afterwards. We'd think that this would stay important, but her storyline disappeared from view as the series rushed to meet its end. Although this story is picked up in Legends of Tomorrow, we are missing key points from the storyline in Constantine.
1 Manny And The Rising Darkness
Constantine learns that nothing would stop the rising darkness and that it was being brought by someone in his inner circle. We learn that Manny is part of this. La Brujeria answer to him, and they are trying to bring the rising darkness. It has taken Constantine a while to trust Manny, but now that he does, Manny has been betraying him. It makes us wonder if Manny has been the one who orchestrated all of this from the start. After Liv didn't stay and fulfill her potential, Zed started having visions of Constantine. Manny appeared to have brought a person with the needed abilities to Constantine. Manny's role with the rising darkness was a cliffhanger reveal. Unfortunately, we didn't have another season to flesh it out.