Sorry If You Answered This Already But I STILL Don't Quite Understand Why Dazai Is Mad At Ango Because

sorry if you answered this already but i STILL don't quite understand why Dazai is mad at Ango because Ango practically had nothing to do with Oda's death in my POV?? Like they were all just pawns of Mori so methinks that the entirety of Dazai's wrath should be directed towards Mori instead.

Anon, I was discussing your ask with @empathique today, and we both understand where you’re coming from. Rationally and logically, we all know that Mori is the mastermind behind bringing Mimic into Yokohama and causing Oda’s death, and Dazai knows that as well. That’s also why we both see Dazai as unreservedly hating Mori a lot more, because if there is a fault, it lies squarely with him. 

However, for many, many complicated reasons that have tangled into an impossible web, Dazai is unable to bring himself to forgive Ango. To begin with the most straightforward of reasons and to work towards the complicated ones…

1. It cannot be said that Ango has no fault in Oda’s death. Despite the fact that Ango was manipulated by Mori as well, Ango played a crucial role in opening the channel for Mimic to enter Yokohama, and given that the government wanted the mafia to resolve the issue, it can certainly be seen as the government making the mafia do the dirty job. Ango is complicit in this, however much he treasures Dazai and Oda as friends. His action is one of the many factors that led to Oda’s death, and Dazai will not and cannot easily forget this. 

2. That being said, Ango’s part is merely one of many factors. These are some of the other factors: Mori masterminding the entire situation, Mimic killing the children, Gide and his soldiers’ pride and honour, the country that has smeared their name, Oda being blinded by the desire for revenge and refusing to listen to Dazai and Ranpo, Dazai understanding Mori’s scheme too late. Just as it can be said that it’s not one person’s fault, it can be said to be everybody’s fault as well. And that includes Dazai’s fault in this entire situation. 

3. Dazai is a frighteningly intelligent man, and hence I wouldn’t be surprised if, as much as he blames Ango, he knows Ango is not the only one to blame, and he has a reservoir of self-hatred for his own part in Oda’s death. However, Dazai is terrible at confronting his own demons—if his philosophy of life is that he is prepared to lose what he really wants the moment he gains it, then he has resigned himself to not forming valuable and long-lasting relationships in order to protect himself from pain. But he has failed here—he has formed important relationships in the form of Ango and Oda, and now he has lost a friend who understood him and who was important to him, and he absolutely cannot handle this. A defeatist philosophy like that he has held cannot produce any healthy healing or processing of his own guilt. 

4. If he cannot accept Oda’s death, if he cannot handle Oda’s death and his own regret in a healthy way, then where does that lead him? In Dazai’s case, it has led him to joining the ADA because Oda wants him to take the path that saves people, and not because he truly believes in the ADA’s purpose. He still has not found a reason for living, and he still has not overcome his guilt. In my opinion, given his lack of healthy ways to grieve, it’s no wonder he’s so angry at Mori and Ango; but Mori is a much, much more dangerous target, more intelligent than him and entirely capable of ruining all that is precious to Dazai, making Ango an easier and, in some ways, a much more personal target. Hence, I believe Dazai’s wrath at Ango stems from a much more deep-rooted wrath at himself and an inability to move past Oda’s death. 

5. Furthermore, given the nature of their friendship (in the sense that the friendship is formed only among the three of them in the bar), with Oda gone, Ango serves as a walking, living, breathing reminder of the friendship Dazai desperately clung onto. Looking at Ango is as good as being reminded that Oda is dead, that those days in the bar are over, and that both of them failed Oda. Hence, while Dazai deeply loathes Mori, his wrath towards Ango is a lot more personal and it contains a lot more pain. 

6. And what would come of it if Dazai forgives Ango? Forgiving Ango would mean, to Dazai, moving past Oda’s death. Given everything that has been discussed above, that is an impossible task for the present Dazai. He needs a lot more time and to find a reason for living that truly comes from himself before he stops clinging onto Oda’s words as his only lifeline. For now, he remains a sharp, intelligent, terribly lonely child who is wandering lost, and such a person is incapable of the grace of forgiveness, whether it is to a past friend, or to himself. 

Please note this is really a personal interpretation and others might think very differently. I hope this addresses your question!