A guild for magicians headed by Kielnode Chrishi and home to the famous Black Magician. Appears to have a rivalry with the Association. Not much is known about Opion as aside from Rood and Kiel, there are no other mages of note.
- Out of Focus: Aside from the first few chapters, Opion is rarely mentioned or seen until much later in the story and even then, we never see anyone else aside from Ren or Kiel.
- Small Role, Big Impact: If Opion didn't come into existence, Rood would have never gotten the mission to infiltrate Helios and befriend Lidius, meaning most of the plot wouldn't have happened since he wouldn't have went to Helios. It's funny to think that the guild with one of the most powerful magicians in the entire freaking world isn't that involved within the plot of Black Haze.
Awakened Name: Blow
The protagonist of Black Haze. Discovered as an amnesiac child by the master of Opion, he has since become a talented magician, even earning the infamous nickname of being called the "Black Magician", though he is only known as such under his Awakened name, Blow as his true identity remains a closely guarded secret. Rood is clever, devoted, and resourceful, all traits that come in handy when his master sends him to Helios with the task of protecting Lidusis as well as experiencing a normal adolescence.
As Blow, he acquired almost instant fame during a vaguely alluded to incident that took place a year prior to the events of the story. His specialty is dark mana, and he usually wields a cross-shaped weapon.
It is eventually revealed that he merged with the king of demons after he was used in the Tower's ritual and was subsequently revived in the demon world by its deposed king. Currently in hiding from the Tower (though right under their noses) after being falsely accused of having had a hand in orchestrating the attack on Helios.
- 100% Adoration Rating: There's not a single person in the world of Black Haze that studies magic who hasn't at least heard of the "Black Magician" and under that disguise, Rood has gained the admiration, respect, and curiosity of nearly everyone that matters in the world of magic. Helios Academy has become a prime example, where after he saved the students in Ishuella, merely mentioning his name towards the students can earn starstruck gazes (especially from Linus).
- The Ace: Despite being only a teenager (or rather looking like one) and the same age as the students that attend Helios Academy, Rood has proven himself to be a highly skilled magician who can complete nearly every mission he's assigned (if Kiel would actually give him proper missions). Monsters that lower ranked magicians couldn't even dream of taking on are nothing more than cannon fodder to Rood when he awakens and he's also highly perceptive, incredibly tactful, and is a smooth talker. There's a reason why he has so many admirers when he sheds his short teenage body and takes on his handsome, tall, and suave awakened form.
- Action Hero: Primarily as Blow, though Rood is hardly a pushover.
- Bad Liar: And hardly even makes the effort sometimes, especially in regards to his Ill Boy status.
- Badass Bookworm: Not just ridiculously powerful, Rood is also highly intelligent as well as he was the first person who applies to Helios Academy that got a perfect score (though truthfully, Kiel pulled some strings as Rood never actually took the test).
- Badass Cape: Usually seen sporting a pitch black cape whenever he awakens.
- Bad Powers, Good People: It's all but confirmed that Rood's power (when he awakens) are a manifestation of his previous life as the King of the Demon World, which by default are considered "evil". Still doesn't stop him from using those very powers to protect everyone around him.
- Big Damn Heroes: Pulls off numerous cases of this that continue to raise his reputation to the general public, such as when he saved the students in Ishuella and after that, saved them again when the demons had attacked Helios Academy.
- Blood Knight: Downplayed. Rood clearly has no problems with fighting monsters (even showing mild amusement from time to time) but has no desire to seek out strong magicians on the same level as him. Shicmuon would be Rood's complete opposite in this regard since he follows Rood wherever he goes just to try and get Rood to fight him to the death.
- Bully Hunter: His mission to help Lidius aside, Rood has no tolerance for individuals who mistreat others for no good reason and makes it one of his favorite past times to issue sweet payback to assholes who have it coming. This is what also makes Rood so endearing to his fellow classmates that begin to look up to him as they were all scared of being bullied but began to change because of Rood's courage.
- Bishounen: Both Rood and Blow, though Blow definitely counts more due to the increased height and maturity in his face.
- Chick Magnet: Certainly so, as the "Black Magician" is apparently very popular to the majority of females such as Serin (a singer who performs for magician parties). This isn't even mentioning how flustered girls can get when they get a look at Blow's handsomeness.
- The Charmer: Commonly uses cunning, cute, and threats to get his way.
- Combat Pragmatist: Unlike Shicmuon who will throw all sense of reason away when he's engaged with an enemy he wants to kill, Blow doesn't play around and tries to finish fights asap, even if he has to resort to using underhanded tactics. A prime example of this was during his first encounter with Eljeble who attempted to prevent him from saving the students from Professor Hiel; Blow promptly slammed him into a wall while he was talking and went on his merry way.
- The Comically Serious:
- Deadpan Snarker:
- Dark and Troubled Past: He suffered in many of the same ways Kiel did due to being an illegitimate child. After his mother died, he went to live with his aunt and uncle who starved and physically and verbally abused him. When he discovered it was his uncle who killed his mother in order to claim the money Kiel was sending her for his care, he was sold to slave merchants and then taken by the Tower to be used in their ceremony. All the while, he hoped that his big brother had read his written plea for help and would rescue him but inevitably ended up dying as a sacrifice in the demon world. After he was revived, he had no memories of his past but has thankfully been living comfortably since in Kiel's care.
- Glowing Eyes: Blow occasionally gets these.
- Guile Hero: Primarily approaches conflicts as this before being forced to resort to violence.
- Ill Boy: Pretends to be one as part of his cover story for why he was a month late to Helios.
- Instant Fan Club:
- Rood gets one on his first day due to his "ill genius" image.
- Blow got one after the incident that initially made him famous. It later expands to include first the Helios underclassmen after he saves them in Ishuella, then the upperclassmen when he saves them during the attack on the school.
- Living MacGuffin: After he is revealed to be the Black Magician and the Demon King. The Tower considers no sacrifice too great to capture him.
- No Social Skills: When he isn't trying to manipulate someone, he tends to be a bit insensitive and awkward.
- Paper-Thin Disguise: His disguise as a magic student. It's mostly his youth that keeps people from discovering a magician immediately, but he has no perspective on how normal people act.
- Secret Identity: As the Black Magician Blow.
- Sexier Alter Ego: Blow to Rood, which Master exploits to get him jobs early in the story.
- Soap Opera Disease: The disease Rood allegedly has that kept him out of school for a month. He makes up random symptoms (most commonly head- and stomachaches as well as a generalized "not feeling well") when he needs to get out of a situation.
- Socially Awkward Hero: While he's a very competent magician, he doesn't seem to know how to act in a social setting.
- Tall, Dark, and Handsome: As Blow — and he's quite popular for it.
Awakened Name: Danteors
Rood's adoptive father and the head of Opion. Formerly a prodigal magician employed by the Tower, Kielnode abruptly cut ties with them after being involved in a disastrous incident and subsequently went on to found Opion. He was the one to discover Rood and raise him. He generally has a playful disposition but knows when to get serious.
His ability is transformation, and he can changes his appearance at will.
Currently being held at the Tower after being forced to rejoin their ranks in exchange for his life and as punishment for killing the five Tower magicians who witnessed Rood's revival eight years ago. He is also revealed to be Rood's older brother.
- Adorkable: Especially when he's trying to act like a concerned father towards Rood.
- Big Brother Instinct: Towards Rood, though Rood doesn't know it.
- Knight Templar Big Brother: Crossed into this when he ruthlessly and with no hesitation killed five of his colleagues in order to keep Rood's revival a secret.
- Dark and Troubled Past: Being the bastard child of a nobleman who's already married with two kids isn't going to win you much favor with said wife and kids.
- Death Seeker: After he lets Rood die, he becomes this, using himself as the sacrifice in the final ritual.
- Failure Knight: Played with a little in that the person he failed to protect, his younger brother Rood, ended up being revived after being used in the Tower's ceremony with his memories stripped from him. With this second chance, Kiel is absolutely determined to keep Rood safe this time around, with Rood none the wiser about the true significance of Kiel's devotion.
- Important Haircut: He gives himself one when he rejoins the Tower.
- Married to the Job: Not so much as the master of Opion, despite being the head of an entire organization, but played completely straight when he was working for the Tower, making it his life's goal to get to the top so that he could then laugh at all the people who doubted and mistreated him in his life. This trope is ironically what leads him to give up everything for the sake of the younger brother he fell in love with and became determined to protect, for if he'd paid more attention to said brother rather than his job, he would have realized he was in immediate danger in time to protect him.
- Papa Wolf: Don't mess with Rood while he's around — you'll come to regret it.
- Parental Substitute: He acts as one for Rood and dotes on him as a father would.
- Promoted to Parent: He's actually Rood's older brother.
- Social Climber: When he was younger, he was willing to do anything in order to make it to the top of the Tower so that he could look down on all the people who once looked down on him. And then along came Rood to change up those plans...
Opion's secretary and a bit of a nurturing figure toward Rood. She's one of the few who knows his secret identity as Blow. Helpful and level-headed, she's often the voice of reason when no one else around her is.
She is not a magician herself, though she is capable of using various scrolls.
- Know When to Fold 'Em: When things get unexpectedly heated at the auction house, she urges Blow to escape with a teleportation scroll even though he hasn't completed his mission.
- Locked Out of the Loop: After the attack on Helios arc, she has no idea that Master, who said he was merely going to visit Rood and never came back, has been arrested, nor does she know why the Tower magicians that break into Opion are searching for Blow.
- However she does find out the first part.
- Non-Action Guy: A rare female version. She's not a magician and thus doesn't fight, despite the sheer number of female combatants in the series and the expectation to be a magician, given that she works for a guild of them. She can hold her own with defensive scrolls, however, and has been shown to occasionally accompany Blow on his missions and bail him out if he gets into trouble.
- Only Sane Man: She oftentimes comes across as this, especially when Rood and Master are in the middle of a father-son spat.