Ao no Exorcist was my most hyped show this season, but since I read the manga, I'll probably be that annoying guy that complains about them omitting or rushing something. Despite that, enjoyable first episode. I watched the first season so long ago, I forgot how many memorable voice actors are in this. Hana Kana as Shiemi, Yuki Kaji as Konekomaru, that guy who voices Zoro and Hijikata as Bon. Crazy.
Still...I'm surprised they basically ignored the conclusions to the first anime. Back before the season was announced, I was expecting it to be like Fullmetal Alchemist, and start fresh with the introduction before getting into the manga material, but it's just starting right at the plot divergence from the first anime. I guess this anime's target audience is mostly people who read the manga...or just forgot what happened in the first one. *shrug*
Your post was really helpful. I watched the first season a few years back now, and I had forgotten basically everything that happened. The new season is consistent with the first season up through portions of episode 17 based on my rewatch. Looking at the synopsis for the other 10 or so episodes, I vaguely remember them, and I'm kind of glad I mostly forgot them. The plot really went off the rails and just went worst case scenario without leaving any room for real character growth. There was no reasonable way to pull the show back on track from that filler arc, and making it at all was kind of a mistake.
Overall, I'm somewhat glad they decided to stick with it since I didn't need them spending 12 episodes recreating and consolidating the first season, but it makes episode 17 of season one weird. Without it, you won't fully understand where the show is at in the first episode of this season, but with it, you already have first interactions between Rin and everybody else that suddenly don't matter because this episode recreated those interactions on the train. It should be more of a clean break from here on out, but it was kind of a sloppy way to continue the series, even with the flashbacks for the sake of solidifying what events were actually relevant from the end of the first season's canon episodes.