There are things that just do not make sense in this fantasy-horror-magic-school book series. The main character Damien (Yes! like the Omen's Damien, the Anti-Christ character in that book and movie series)... at age thirteen creates a special rune (without any real rhyme or reason) and summons one of the most powerful Eldritch Horrors, "It Who Heralds The End Of All Light" called "Henry". I find it hard to believe, that the main character has a name related to the Anti-Christ while one of the biggest demons, that could wipe out all of humanity in an instant is called "Henry" (like Fonzy or Dr. Jones)... Damien gives half of his mind and soul up, to have a contract signed with "It Who Heralds The End Of All Light" who believed that a 13 year old child had at that age and time the power to vanquish (the terrible and all-powerful demon)...
Supposedly Damien has this incredible desire to learn magic, but from 13-17 years of age, doesn't do a single thing about it, not even ask his Mom for help or books, Damien just tries and tries to wake up "Henry" but to no avail... In the moment of truth, at the exam to test "magic potential", Henry shows up by himself, without being really summoned and starts taking over Damien's life. Although the name of the magic school (with only the combat class) is Blackmist, the grand demon "Henry is not a blackmist" but a demon that constantly lives within Damien. He can travel outside as a "blackmist" to see the world (because there is really nothing to restrain him and Damien does not have character or strength to stop him) and this is moment of the story when "Henry finds out that there are currently 5 Mega Demons out and about in the World and that it's just a matter of time before they destroy the World.
So, the theme of this Fantasy-horror-magic-school story is that Damien, without any magical ability or skill (he just knows some basic runes), needs to "urgently" learn magic and become all powerful to stop the Greater Demons, that are unleashed from destroying the World.
The magic school is a little bit too similar to Harry Potter's (with the students that have rivalries, dorms and duels)...the author finds nothing wrong with rooming Damien with a girl called just Sylph (no last name) (does not explain anything about her, or the other characters, by the way), who is probably the most experienced and strongest in magic at the first year of this "magic school"... The author does not explain how magic works in this "other World"... Somehow with the spirit familiars, the students and magicians "borrow their power"...But it's not like that all of the time, because there is one particular person, that does not have a "familiar" and can cast magic...(who I will not name for spoiler's sake)...then Damien who could not even "boil magical water" seems to be able to do it all in an instant and at the drop of a hat?? This part of Damien's magical abilities lack real balance and actual learning, merit of having learnt, etc. etc. etc.
So, the worst possible Eldritch Horror, does whatever he wants, in this World thanks to Damien letting him out...and "Henry" instead of destroying the entire World and ending this fantasy novel series once and for all, slowly but surely teaches Damien the magic that he needs to "protect his conversations", "have a magic place to train", etc. etc. Is that how a mega-demon is supposed to behave? It seems that Henry wants to destroy the other 5 demons more than this World. Which is contradictory to his life-long desire to destroy the World???...Was Henry corrupted/deflated by Damien his "best-friend"???
The author could take this story "anywhere"... Damien doesn't really learn from his teachers, he learns from Henry, so why go to the Magic School??? Sylph doesn't have any money, and Damien hasn't worked a day in his life and yet, Damien pays for Sylph's meals and things??? Did the author forget to write the part in about Damien being affluent or winning the lottery in another world???It's a magic school story, and the main characters seem to have only one class?? (combat class)??? What happened to the "alchemy", "rune", "dark-magic", etc. etc. classes???? Did the author not see/read the whole Harry Potter series??? Or was it boring to write all about the other teachers and other classes?? Then, the students participate in a "competition"...But they are studying only the "combat class"???
Same thing happens with the RPG-game-like system this story "should have" but doesn't really include it... the "students" have a way to "read their stats" (HUD-head's up-display), but do not have a leveling system, a magic grimoire-like for learning spells, they do not even use a "staff or a wand/broom" to "empower" and direct those spells (or fly)...do not use a mage's robe, or any other equipment that is typical in magical school stories...So, is Blackmist "college" (that is a one-class school) a "Gladiator-Mage Dueling School"???
The author seems to be on the "younger side", so maybe the inconsistencies of this fantasy story are because of a lack of reading classic literature novel background, lack of emotional intelligence and a lack of rational/logical classes at least in High-School/University level... Knowing how to write, and knowing what to write are as important as having all that is written make sense (rational, logical and use common sense). Having just two, without the third part, makes it a three-legged-stool that can fall at any moment...