Try listening to "Tsubasa Wa Pleasure Line" and "Sayonara, Solitia" without feeling the least bit emotional.
Much of Hikaru Nanase's score is very good and some tunes can tug on your heart strings plenty.
Complete Monster: The anime incarnation of Aion is stripped of his original counterpart's redeeming qualities to become a remorseless seeker of ultimate power. Having decapitated the leader of Pandemonium, Aion uses her severed head in his ritual and sparks a war in the demon world that kills countless millions. Tearing off the horns of fellow devil Chrono for showing remorse, Aion bestows them upon the young Joshua Christopher, uncaring that they drive the boy mad and lead him to petrify everyone from his orphanage. Taking advantage of a lonely woman, Aion manipulates her into killing an entire town of people as a sacrifice to him, delighted in the control he holds over others. Conducting his ritual for godhood, Aion nearly destroys San Francisco, and when Joshua's sister, Rosette, seemingly stops him, reveals it was her powers he wanted after all. Brainwashing her into becoming his slave, Aion entrances civilians with her healing powers before declaring himself a prophet who has deemed humanity sinful and demands they kill each other. Despite knowing the cost of his power is the destruction of both Earth and Pandemonium, Aion is utterly apathetic to the deaths of billions.
Evil Is Sexy: Aion, particularly the anime in which he exploits his sex appeal to both draw in allies and screw with the minds of his enemies.
Mind Game Ship: Nearly all Aion/Chrono fic portrays the pairing as this.
Azmaria's main purpose in the anime and a huge factor to her character in the manga as well.
Joshua as a kid he seems to be – a bright young boy with feelings of inadequacy and constant illness. When he's older he can sometimes be this way, too, although the fact that he's blissfully working for the villain and absolutely off his nut seems to invoke the opposite reaction in some people.
Too Bleak, Stopped Caring: The anime adaptation suffers from this, since (almost) all of the characters die with none of their plans succeeding in any way and the villain never gets any kind of comeuppance (he might have died, but it is unknown). The anime is infamous for its killing off and/or mental breaking of major characters who survive the original manga. note Most notably, Shader, Fiore, and Satella are all alive at the end. Joshua recovered his mind and joined the Order; it's heavily implied he and Az became an item. Steiner does not die during the Battle of San Francisco (though given his advanced age he probably doesn't live too long after). Even Rosette lived for seven years after the final battle instead of the six months she had in the anime – granted in both continuities she spent the entire time on the brink of death.
What Do You Mean, It's Not Symbolic?: The manga plays it fast and loose with the Christian symbolism. Indeed, come the reveal that the Sinners are aliens, one wonders why any of it is there at all. The anime, on the other hand, averts this by playing up the Christian imagery to the hilt and making everything very symbolic.