Not surprisingly, the show, true to it's harem and ecchii genre, is heavily built on fanservice as well many types of embarrasing,teasing and erotic moments, so it's probably worth noting that those that expect an incredibly, outstanding story will probably be disappointed.
THE STORY
In summary, the story starts with Issei and friends in a trip to hell, during their vacation, in which rapidly envolves them in the great conflict between mythologies and the terrorrist organization called "Chaos Brigade", and so our heroes must train to become stronger, while at same time they also have to deal with their "it's not end of world" but struggling highschool lives. Also worth noting that there are subplots in which our character must help their haremettes with their individual struggles.
One problem I faced is the oversaturation of mythologies in one story. Like how does it work? Each religion comes with it's universe that most likely contradicts the story of others... like who controls hell? Lucifer? Hades? Hela?
World building isn't one of the show's strentgh. Hell doesn't have such a cool and diferents scenarios. Also, although the story revolves about this great mythical war, it isn't left much for the audience to understand it's implications. For one you would something of this scale could greatly if not completlly fuck Earth as we know it, but the topic of how this affects Earth is never mentioned. The audience never feels like a real war is happening. Of course there is a great battle at end, but the enemy is pretty much pulverized and real tension never comes and number of dangerous players in the battle isn't very balanced... Azazel,Lucifer and Odin against who again?. It is mentioned that the Chaos Brigade is constantly attackin the underword, but we never see this or it affects our characters in some meaningul way. The battle against Loki is somewhat nice, but let's be honest... it's really inpractical at all. You are sending a bunch of low level devils agains a F***ING god?Really?
Art & Sound
There isn't much to say really. The art continues to be incredebly appealing with the various despictions of the girls and the music isn't so memorable.
Characters
First as always, the protagonist. Issei is a guy that I have found struggle to like. His portrail of a clueless chick magnet, to me, always enters in conflict with the idea of him being a "chivalrous pervert"(which is something I don't believe). He manages to get every girl in the group to fall for him, but when the big moment happens, he doesn't go for the kill. Yeah yeah, there is the curse thing, however such obviouness is insanely ridiculous to point that it becomes annoying that he doesn't think the girls have thing for him when they are literally wearing sexy clothes and throwing themselves on him.
The girls in general receive some character depth and development. Yet it feel like somethings haven't changed. Rias, for all of her jealousy about Issei and the other girls, is still left without a resolution because Issei never comes with terms of having a single girlfriend or a whole harem, putting the issue back to square one. Akeno has aparently resolved her issue with her father, which made her have a negative view on men, while having a illogical attraction for a pervert who seems like the only one with morals. Well, at end she is still very much dependable of Issei. Asia seems to be always put in damsel in distress and her shy attitude doesn't change. I honestly think someone should teach her some fighting skills, but who am I...
There is also Yuuto and Gasper... well they exist I guess? One is a pretty boy and the other... a prettier boy/girl?
Koneko gains a much more visible development and still remains a likeable character for being the only one who shows some resistance to "Issei's charm" and for being a character who has a personality of her own without being related to something necessarily sexual or erotic.
Characters like Vali, Sirzechs, Azazel, the student council, etc are tolerable and even likeable, although are so much highlighted.
The villains continue to be one dimensional and well...horrible,disgusting and evil for no other sake.
Enjoymet & Overall
There can be times when it's enjoyable for it's fanservice even if they sometimes distract the viewer or seem inapropriated in a moment that should be treated seriously. Still, it never manages to become better than it's predecessors, by trying board a bigger story that never is more than superficial.
