I find it odd that while the anime had a lot of bad reviews this manga isn't known at all.

Story: 8
Let's just say that the plot isn't the best I have ever seen, but it has a lot of originality in it, like as other works from the same authors, the fact that demons are actually less evil than angels in the end is one of the points I liked mostly. Even though the series is quite new, it needs more time to fully develop.

Art: 10
This was absolutely, the most gorgeous, magnificent, and most elaborate manga I have ever read, you should definitely take a look at it if you like amazingly drawn manga, because the art is one of the biggest point of it.

Character: 8
The characters from Makai Ouji are incredibly various, from saints to people that really existed in history. The main character has his unique charm which is being an absolute realist to the point of even contradicting himself, most demons have a well developed backstory and not all of them belong to the same faction, which makes the thing much more interesting and intriguing. Just because it has a large cast of male character, it doesn't mean women are useless in the manga, but it's a josei manga after all.

Enjoyment: 8
If you're looking for something original, you'll definitely like the manga, if you like the action themed genre you'll also enjoy it, apart from some chapters that are almost useless, the pacing is very quick.

Overall: 9
Don't let yourself get fooled by the poor anime adaption, this manga should become more popular as it has a very high potential, it shouldn't also be overlooked or underrated, it's kinda like an hidden gem of manga.