To be clear it's not just another rant because I am salty kid and my favourite character died or something and that's why I gave 1 to this season. Just kidding it will be salty rant with little of arguments why I think this season is complete GARBAGE. I watched 1 and 2 season 7 years ago and I was more than happy to hear that this show finally is getting attention and moving forward with the anime. I enjoyed 3rd season even tho it had some problems with animation, plot and I could not force myself to like those characters like I was few years ago. That being said season 3 had some good character development with that fox girl - Izumo. However i cannot accept how dogshit this (4) season was overall. We were witnessing Yukio becomeing some kind of evil twin for like half a season and it was shown like in some very old trash show for a dumb kids. It wasn't not a bit interesting, it hasn't been a not even bad plot twist because there were no plot twist, being an adult I couldn't even get why in the first place he had his fight with Rin and he screamed at him like a madman instead of having an conversation. He has like a 30 seconds of good plot around Shiemi when he went to her house and that's it, all he did in this season was becoming emo 13 yo sasuke laugh/faces and he isn't even cool like sasuke was for some time (wtf how is it even possible not create that bad character). Next being said the plot around Shura was like low mid tier at best and I was really curious about her before that season aired. Now she is some random with big boobs. The best thing in this season was Lighting relationship and plot with the Suguro. But he even changed his hair I feel like just to angry me. Overall last episode when all the 'reveal' and all the feelings that they were hiding inside should go out it was completely trash. I mean autor just mixed up Sasuke leaving Naruto first time and Ichigo having a first conversation with White. They mixed it and did it so dirty I want to hurt myself thinking about it. ( I finished this episode like 1 hour ago and still can't get past how BAD it was). I even checked the manga chapter that has been adapted to this horrible episode, because I though it some bad Christmas joke. I am so sure I haven't watched anything worse than this episode for a like 3 years and I watched a lot of good/bad/mid/horrible stuff in that time. This season was such a dissapointment that I can't handle it. If someone managed to get to end of this review I think either you will shittalk me in comments or you completely agree with me. If you are the first type of person, feel free. We all can have a mixed opinion about something.
Above being said I think that overall world plot is not so bad. I am still a little invest in overall plot with Satan, Illuminati etc but these characters at best few are mid and all others are like npc or some 3rd plane type of characters in other shows like My Hero Academia, Hells Paradise. Even in those series I feel more connected to 3rd plane type of characters more than for Ao no Exorcist main cast (with few exceptions). I will give another chance since I barely drop any shows. I mean I prob only dropped Boruto xD I even finished Nanatsu No Taizai after Meliodas vs Escanor abomination of episode and an animation. I think if someone really likes the chemistry of these characters and if someone think that the plot around Yukio and Rin is something of likeable or good please explain it to me because maybe I missed like few episodes of backstory or something.