Soul Cartel follows Si-un Cha, a young Korean boy who is able to see the spirits of the dead. He is taken care of by his older sister, and comes from a family of powerful mediums and exorcists. Sadly, Si-un Cha himself is lacking in any spiritual abilities whatsoever aside from his ability to see spirits. Despite this, he tries to help his sister catch weaker wayward ghosts. When chasing after one of these ghosts, he runs into a very powerful demon.
The demon claims to be
the Mephistopholies, who wants Si-un Cha to teach him of the modern human world and bring him books about his exploits. He states that if Si-un Cha tries to run away, he's done for. Si-un Cha does have the common sense to consult his sister (without revealing that he's actually
caught a powerful demon's attention), but he quickly learns that even his sister would be no match for Mephisto. After Mephisto finishes a copy of
Faust he reveals that he came to earth because Faust has been reincarnated. The
real story of Faust was that Faust was an arrogant human who'd claimed that he would not be corrupted by Mephisto's temptations, so they'd entered a contractual wager, with God acting as the judge. However, God had unfairly intervened at the last moment and cost Mephisto his victory.
Mephisto does in fact find the reincarnated Faust: He's a now a
Teen Genius, Damian Lia, with his memories left in-fact and of about Si-un Cha's age. Faust states that he'll enter a rematch with Mephisto. This time the bet is if Faust can get Mephisto to become a kinder devil within the Underworld, it's his win. The catch? Mephisto thinks that he'll be cheated again if God is the judge, so he appoints Si-Un Cha to act as one!
Tropes associated with the Soul Cartel manhwa
- A boy and his super-deformed demon.
- Always Lawful Good: Every Angel seen so far has been unambiguously good. The only only exceptions were two Asraels who were searching for Mephisto. That is, two angels who wanted to keep a very powerful and potentially violent demon out of the human world.
- Anime Catholicism
- Bad Ass Abnormal: It turns out that Si-un really DID have powers.
- Bad Ass Long Coat: All Azraels wear long, white, hooded coats.
- Big Damn Heroes: Mephisto in chapter 55.
- Bishounen: Damian/Faust, and Michael. Also Mephisto when he stops holding back.
- Blue and Orange Morality: Mephisto has this in regards to his appearance. He thinks his small and short form is cool, and calls it a "Devil's aesthetics." Even the angel in their group is confused by it.

- Blazing Inferno Hellfire Sauce: Ddeokbokki, also known as spicy rice cakes, a super-spicy Korean dish. And Mephisto loves it!
- Chivalrous Pervert: One of the ghosts takes quite a liking to Su-in for her beauty and figure, so he follows her around on exorcisms and helps her out.
- Curtains Match the Window: All witches have both purple hair and eyes.
- Cute Little Fangs: Mephisto.
- Cute Witch: Airen.
- Five-Man Band:
- Genre Savvy: Si-un knows how ghosts and demons try to trick people, knows when he's in a fight he's outmatched in, and has the common sense to consult his sister after he's gotten Mephisto's attention.
- Guile Hero: Faust shows shades of this, convincing Mephisto that the best thing to do in his favor would be to fight the Azraels in the Underworld in order to prevent any collateral damage befalling the physical one.
- Hot Witch: Higher-ranking witches look like young, attractive women with purple eyes and hair.
- I Just Want to Be Special: Si-un isn't very happy about not being able to fight spirits.
- Living MacGuffin: Faust, Si-un and Su-in are unfathomably valuable to demons because of their young human bodies. In Faust's case, they don't even have a number big enough for him.
- The Load: Si-Un's status as this is lampshahded here.

- Long-Haired Pretty Boy: Some of the angels, Michael especially, and Mephisto is a rather cartoony version until he stops holding back, then he becomes a much straighter example.
- Purple Eyes: Every witch seen so far.
- Megaton Punch: Mephisto unintentionally does this to Si-un's punching bag and sends it flying into a mountain a few miles away.
- Oh Crap: Si-Un has this reaction when Mephisto claims that he'll be his next target after he's done with Faust.
- One Gender Race: The Witches, who are all purple-haired, purple-eyed women. They don't reproduce sexually, but by magically splitting their life forces to create new witches, which has about a three-in-ten chance of death for the witches participating.
- Promoted To Parent: Su-in Cha, Si-un's older sister, took this role after their parents' passing.
- Super-Deformed: Mephisto
- Trademark Favorite Food: Ddeokbokki for Mephisto.