If you enjoyed the first 2 seasons in spite of a few absurd story arcs and silly character development, and you're willing to overlook poorly thought out character motivations for the sake of grand themes of heroism then you might be able to enjoy and even fully embrace season 3. I disliked the nonsensical villain motivations in Season 2 and I feel that their motivations seem to make even less sense in Season 3.
Since Season 2, we have seen that most of Hero Academia's villains want to kill All Might because he happens to be the so called "symbol of peace". Why would any villain want to kill the "symbol of peace"? According to Hero Academia, villains want to kill the symbol of peace because they want to deprive Japanese citizens of the hope that any hero can save them from any kind of danger at any moment in time. By the way, we don't really know if any country other than Japan actually exists in this fictional superhero and that just makes suspending one's disbelieve a little harder needs to be.
How exactly does a villain materially or emotionally benefit from depriving people of the hope that All Might or any other hero can save them at any point in time? How does killing All Might or any of the students of UA high satisfy a villain's emotional or physical needs? None of these important thematic questions are ever answered. The sad fact is that almost all of the villains have motives that conveniently push the plot forward and create some much needed suspense and tension. But in their attempt to kill All Might and UA students, the villains have sacrificed their physical well-being and their emotional needs. It makes no sense for villains to have motivations that don't personally benefit them in any imaginable way.
In real life or in stories that have realistic characters, villains have one of the following motivations; greed, curiosity, a lust for power, a desire for revenge, spiteful envy or a desire for dangerous fun. Is it possible to write villains who want to kill All Might or the students of UA High for realistic reasons? Of course it is, but it's generally easier to write villains who exist for the sole purpose of perpetuating a poorly conceived storyline. Made in Abyss and Kokkoku both have villains with interesting and unique motivations that actually make sense. You can check out my reviews for those two anime.
I recommend watching the first seasons of both of those anime rather than watching the 3rd season of Hero Academia, unless you like Hero Academia's world building and you want to find out how the story's going to end. You can watch this shipwreck to the very end, but I'm jumping ship with what's left of my sanity.
Now back to my review. The only one or two villains in Hero Academia have a somewhat realistic motivations and they're just minor characters who get as little screen time as possible. The villain I liked, fights for fun and his goals occasionally conflict with the goals of the Villain Vanguard. He's like a less interesting version of Bleach's Kenpachi. This is actually the least disappointing aspect of Season 3's storyline.
To get to the heart of the problem of villain motivations, we need to examine Hero Academia's most important villain: Stain. In Season 2, we were introduced to a villain called Stain. The extent to which you like Stain's character development will determine the extent to which you will enjoy watching Season 3. If you love Stain then you will love Season 3. If you hated Stain then you will hate Season 3. If you felt ambivalent about Stain's character then you will feel ambivalent about Season 3's storyline.
Villain motivations is just one of the fundamental problems that plague Hero Academia's storyline, but I think the single biggest problem: is Stain's character development. First of all, Stain has no backstory in the anime nor does he have a backstory in the manga. Why exactly Stain set out to kill licensed heroes he thought were fake heroes with ill motives remains a mystery. Season 3 expects us to believe that lots of villains were inspired by Stain's actions, which makes no sense because that implies that lots of villains actually care about the heroic qualities of Japan's heroes. By definition, the word "villain" implies that one has a selfish and self-centered worldview. To truly be worthy of the title of "villain" one's priority should be one's personal well-being not someone else' heroic qualities. You cannot be a "villain" if you selflessly want to better society by purging it of incompetent and ill intentioned heroes. If you had Stain's motivation, then you would feel deeply insulted by the idea of being called a "villain" and you would never associate yourself with someone called a villain. Anyone who claims to be motivated by Stain's ideology would never to call themselves a villain or even allow themselves to be within spitting distance of anyone who happens to have villainous intentions. Horikoshi, Hero Academia's creator, has never described Stain as a misunderstood vigilante and that makes the fact that he inspires individuals who openly describe themselves as villains even more confusing.
Horikoshi also does a piss poor job of convincing us, the viewers, that any so called villain who believes in Stain's incoherent ideology has an emotional makeup that makes even a lick of sense. Humans can have irrational motivations, but even irrational motives make some kind of sense to those who hold such motives. Terrorists and suicidal cult members, however bizarre their motivations may seem to the average person; can easily articulate or demonstrate the motives behind their actions. The same cannot be said for anyone of the villains in Hero Academia.
The other problems that plague Hero Academia's storyline and character development include; Deku's and other important heroes' increasingly powerful plot armor, the nonsensical rules that hero students are forced to abide by for the sake of maintaining some semblance of tension or drama in the story's overall plot, and the subtle but pernicious sexism that undermines some of the series best story arcs.
Since Deku mastered the One for All quirk in Season 2, he has not encountered a villain or obstacle he could not physically or emotionally overcome. Not only does this plot point suck away all the drama and tension we enjoyed at the beginning of series, it also makes the overall plot a bit too easy to follow.
And any hope we had for some dramatic tension later on in the story was crushed by the fact that Hero Academia's plot armor not only protects Deku from being killed, but also prevents him from experiencing any kind of emotional suffering. Since he mastered his quirk, he has not lost a single fight to a villain. If he lost a few fights to some villains once in a while, the story would be a lot more interesting and exciting. Deku's ever growing plot armor makes the story monotonous and predictable.
Now it's time to get into what might be the most controversial part of my review: Hero Academia's pervasive and pointless sexism. There are 3 main problems with the way women are portrayed in Hero Academia. The first of which is the fact that no matter how hard superheroines work, they never achieve as much as their male counterparts even when they have superior quirks. Momo is a great example of this. Her quirk is incredibly powerful and she should be the number 1 student at UA high based on her grades and her masterful control her of work. But Horikoshi never let's her unleash her true potential. There are so many so many things she do with her powers that series never even hints at. She could spawn grenades, heat seeking missiles, ultrasonic guns, tear gas and any number of incredibly useful tools from her flesh. But Horikoshi paints her as a surprisingly unremarkable superheroine with the emotional weaknesses of a stereotypical Japanese girl.
Since Season 2, Momo has not come any closer to being UA's best student despite her amazing potential. Like a lot of female characters in Hero Academia, she lacks self-confidence and believes that she cannot make important life decisions without the emotional support of a man. In Season 3, Momo is relegated to the role of a mildly interesting side character and it's up to the toughest male characters to almost singlehandedly save the day.
Secondly, women are consistently portrayed as being less motivated and less hard working than men for no other reason than the fact they are women. Even if we suppose that women in real-life Japan don't work as hard as men even when they are exceptionally talented, this series forces all it's female characters to never even attempt to push beyond the artificial physical and emotional limits they place upon themselves. It's fine if one female characters fits a certain gender stereotype, but a story in which all female characters suffer from the same female problems is not only less realistic, but also less fun to watch. The 1st episode of Season 3 portrays all the female characters as lazy fun lovers, but portrays men as hardworking and dedicated to their training as heroes. Someone will argue that female social pressure makes the ladies less motivated and a little more relaxed, but that makes no sense in the context of a dangerous and life-threatening school environment where students are attacked by powerful villains on a regular basis. The terrifying prospect of being killed by a villain should be enough motivation to keep any student on their toes regardless of their gender.
And lastly, too many female characters seem to lack self-confidence simply because their women. There are no men in Hero Academia who lack self-confidence and that's really suspicious. Even Mineta, one of the weakest quirk holders and arguably the least motivated male character, never experiences a crisis of confidence or a moment of doubt. He never even considers quitting UA High. In this series women are less self-confident, regardless of how powerful their quirk is, simply because they're women. There is a difference between revealing gender stereotypes and reinforcing them. Hero Academia wholeheartedly indulges in gender stereotypes that weaken the impact of the story. If any of the male heroes questioned their abilities as heroes or decision makers, the story would be more interesting and engaging. What if Deku experienced a crisis in self-confidence? Wouldn't that be fun to watch? Or are all men immune to the emotional suffering that plagues female characters? The fact that men never hesitate or falter in this series, makes Hero Academia feel like a silly power fantasy written by a man for men.
Whether or not you're convinced that Hero Academia's veneer of thematic depth makes it the greatest shonen anime ever written, at some point in Season 3 you're going to feel the crushing weight of all the story problems I've just described.
