I'm a little torn on how to feel about this movie. As a whole, it's great; it has action, betrayal, suspense, drama...etc. It's certainly a good movie, but not one to really watch unless you can give it 120% of your attention. It also has a great deal of faults...one of which legit prevented me from enjoying the latter half of the movie because I was too busy scratching my head in confusion.
The movie opens up with Dazai's days in the Mafia as he and his partner (Chuya) have tracked down a madman who just seems to be throwing gems into a fire for an unknown reason after a bloody massacre of multiple underground forces.
In the present day (taking place sometime after season two of the anime), people with special powers are found dead by suicide one after another in various parts of the world, and the Armed Detective Agency is asked by Ango to investigate.
The typical cast is there, though the focus is very much on Atsushi. Dazai and Kyouka also play large parts, and it wouldn't be Bungou Stray Dogs if Akutogawa didn't show up as well. Sadly, some of the characters take a step back from how they were at the conclusion of season two.
Mori (the mafia boss) also makes his appearance, and there are brief appearances of the others from the Agency.
There's the "demon", someone mostly unknown to people who only watched the anime (as he only briefly appeared at the end of season two), Fyodor Dostoyevsky, whose mind is on a level of Dazai and Mori.
Chuya gets quite a few moments...
...and we can't forget about the antagonist. I want to say "I'll leave that blank for spoilers", but I feel it would be beneficial for a very brief mention of him since he's not exactly a "secret" in the movie. If you truly don't want to know, then just skip ahead to the "Overall" section.
Tatsuhiko Shibusawa is the antagonist here, a new character to the series with a very unusual ability called "Draconia"; an ability which might just have the power to provide energy to the dead (as in, reviving them).
That is not the part of the ability you'll be seeing in the movie, so don't worry...I didn't just spoil it. If I had known that fact about his ability, I wouldn't have been so confused. It's basically something I feel people should know when going into the movie since it's never fully explained.
Be warned, there are a lot of metaphores in this. If one pays attention to those, then the viewer can actually predict certain events which occur later on in the movie (mostly the ones surrounding Dazai).
It's as I said at the start; a pretty good movie for the franchise, and it keeps more along the lines of the second season's slightly darker tones. There are sprinkles of comedy, but not as much as even what was in the second season.
By the way, this is definitely meant to be watched after season two.
On the plus side, there's no repeated footage (finally). Minus side with the animation, there are still talking faces at times (if I recall correctly; I'm guessing that's just going to be a thing).
For the soundtrack, the opening and ending songs were fine, but again they struggled with the BGM in a couple of places (and I really wish they'd stop using that soundtrack of the woman singing that opera-esque song; it just doesn't mesh well and is quite distracting. The instrumentals for that song would have sufficed to generate the mood).
WARNING: SPOILERS BELOW
I don't like including SPOILERS in my reviews, but sometimes it's unavoidable in order to explain why I've rated something a certain way.
Sadly, we have to see Atsushi confront his inner demons...AGAIN.
If this had occurred between seasons 1 and 2, no problem. But at the end of season two, Atsushi clearly accepted himself. Yet, it was made out to be a sticking point in the movie for him to accept the tiger.
Honestly, those parts bored me. What should have been drama bored me, because it's been overused to death. A character having a trauma (and possibly self-confidence issues due to it) is one thing, but season two actually resolved the majority of what he had to deal with in the movie.
The antagonist also apparently had a connection with Atsushi (something most viewers will probably realize early on when Atsushi responds to the name during debriefing)...one which is more of an "oh by the way"...and actually hurts Atsushi's character.
Sorry, but Atsushi was the "innocent" one of the group. Many of the others had blood on their hands from one thing or another, but Atsushi has a strong "no killing" policy. Even uncontrolled, his tiger form NEVER killed a person.
This, according to the very first freaking episode of the series.
Not one person, not even ONE, ever died due to his tiger/beast form.
This movie takes that and goes "yea...let's change it up and make our innocent kid kill this guy...twice". Uh, no. I get that movie events in anime typically aren't considered "canon", but this is taking that too far.
It also first puts Kyouka in a position where she wants to accept her power, then for some stupid reason puts her in a position where she hesitates and has to be told by Atsushi to take control (after literally just accepting it not too long ago).
This also disrupted the flow of the movie as well as character development, and is a huge flaw in the movie.
The biggest flaw, however, lies in the lack of explanation to the antagonist and how he survived death the first time (within the movie; I had to look at a Wiki to find out about it).
The antagonist had died once before, but due to his ability, was somehow able to regain his form due to energy he had collected (from another part of his ability)...though he forgot his memories before his death (and of his death).
While knowing this makes understanding how the heck he was able to stand there and cause so much trouble to the city and characters, it's sort of a dues ex machina to give him and Atsushi a personal connection and reason to fight.
...one which wasn't necessary.
Atsushi would have fought with the same level of strength for the city and the people he cares about; the writers' decision to give the antagonist a link to Atsushi's past was unnecessary and just created way more confusion than it was worth.
The reason the antagonist returned is one thing; that one at least adds into treachery involved when a couple brilliant minds get bored (once again, solidifying my opinion that Dazai ia psychopath).
However, this "returning from death" thing? Even in a world where these God-like powers are normal, that's pushing it. After all, the main antagonist of season 2 was looking for a book in order to overcome death...but then this antagonist just ups and can do it himself.
In terms of action, the movie did well with the fight scenes; nobody sustained fatal injuries and then miraculously survived (perhaps with the exception of one character being stabbed in the back...literally...but my guess is that it missed anything vital and the knife itself wasn't what was meant to kille the character...but we all knew he wasn't going to die because we saw him take a countermeasure to it early on in the movie).
What's sad about this series as a whole is that there's no tension when a character is badly wounded or even slightly wounded; injuries a normal person would have died to on the spot (not to mention the issue of blood loss) these characters manage to live through.
It does mean I was able to go into watching this movie knowing that they wouldn't kill off any protagonists, anti-heroes (the Port Mafia), or current series antagonists (Fyodor). On the other hand, it meant that I wasn't really hyped since there was no sense of true danger to the characters (even when they were in danger).
That little nitpick is just the tip of the iceberg compared to the antagonist being alive when he shouldn't, the unnecessary connection between the antagonist and Atsushi, and Atsushi killing someone after stating throughout the movie that he was NOT going to kill anyone (not to mention it pretty much being his MO).
The movie didn't move me the way Detective Conan movies often do, or hype me up like DBZ movies. It's perhaps a little better than average, but the obvious flaws in the movie sadly make themselves glaringly obvious and take away from many of the pros the movie has.