OKAY GUYS. I marathoned this shit too, and unlike AssClass, I actually paid attention to shit!
So yeah, This series is badass.
there are many things that I like about it, the main concept is very appealing, its well drawn, the pacing is near flawless (when we're into a seriious arc) the fights are good, not technical and pretty simple, but still entertaining, the character developments is a WIN. many characters got it, and it was always well written, in my opinion.
there are many BADASS characters, with unique designs and characters traits that make 'em even bettter, like seriously, jabberwock, Natsume, Kanzaki, the MK5, Tojo, Yuka from the red tails, and there are a shit ton more!
what makes them even better is the interaction between them which ALWAYS lead to something amazing, insanly funny, or even both!
I really like the art, I am enjoying these panels and I believe they were used in a good way.
even the covers, THEY ROCK, my favorite is the one of them playing a video game, it was epic!
and the last thing that I like about it (its not that I liked it less than the other things) is how the mangka of this Beelzeebub doesn't seem to forget about his characters, they're always somewhat relevent, even if its for a comedic scene.
so yeah, and to prove that I went through this shit with my mind on I'll point some flaws:
the way Furuichi characte was handeled for a shit ton of chapters was annoying, I don't like him that much, but the way he was always getting his ass kicked for a reason or not was somewhat.. disturbing. its true that he redeemed himself in the tissues mini arc (whatever its called) and in the last few chapters where he was acting as the tactican, but what happened happened, he still looked like shit.
the second flaw IMO is how some fights can get TOO simple AKA I've got a new power up and I am gonna kick your ass.
the third and the last is the king crest, its just a way for the tohoshinki guys to get more powerful so they can still be releavent against demons and spell masters, but yeah, it was kinda forced so MEH.
I was also going to say that there were so many chapters that never was important because I am sure a lot of people wanted some dead serious action most of the times, but fuck me, I actually like these little funny arcs, so no, I am not counting this as a flaw.