Writing this review just to say that the anime only ending was infinitely better than what happened in the manga. It's what solidified it as one of my childhood best animes. Season 2 was so sad and annoying. Everybody is so annoying and stupid in season 2, because the anime only ending didn't happen. I think what I like most about Blue Exorcist over similar B tier shounens of this era is how brisk the pacing is. It never stays on the same thing until you get bored. It never keeps an annoying character or plot point mind-numbingly annoying for long (I think one of the problems that really stands out about shounens in this era). Except that in season 2, when the thing that removed the most annoying characters and plot point in the series gets canceled because it's not manga accurate, it gets really bad and annoying.
Art: good, unique, allies outside of MC and main girl kinda suck, but the overall art deisgn, world, and pretty much everybody except for the those allies look really good.
Sound: idk
Story: again, i liked the pacing. The anime only ending was really interesting for younger me and shaped how I approach a lot of difficult issues.
Characters: MC, MC's brother, MC's dad, MC's other sorta relatives dynamic is great. The villains are great. The allies are good only in the anime only ending. They suck in the manga/season 2.
Sorry for bad review. Again, just wanted to say that the anime only ending was infinitely better, and one of the best parts about the show.