MyOwnGod said:One Punch Man+Harry Potter, what can go wrong with such a great idea? Mashle isn't actually bad, but as can be seen from the ratings, it fells flat despite its potential. The interesting thing is that it even has well-developed characters, unlike most anime, including Eminence In Shadow, which succeeded with a similar "OPM" approach. So, what's the problem with Mashle?
I think it's in the inconsistent tone of the story and lousy world building. Serious fights are interrupted with silly comedy, and stakes aren't clear enough. I mean, do characters actually try to kill or permanently harm each other? Or are such fights normal for mages and aren't deadly? Is it okay for students to murder each other in the academy? We don't know. The author should've chosen one of the two paths. Either make the world clearly brutal, like in Dorohedoro, where it's common for people to be killed, where mages are merciless to humans and each others. Or make everything "safe" like in My Hero Academia, where it's established that the fights between the students are normal and not deadly, unlike the fights with the villains. It's either one or another, but Mashle just doesn't make any distinction, thus in one episode we have death threats, that are never fulfilled as no one in the first season ever dies or is even disabled, and in another the former enemies become friends.
Be it OPM, Mob Psycho, or Eminence in Shadow, we have a serious world that, if we remove the main character, will function like one. Those stories work so well because we add a "foreign" element in the face of the protagonist into a serious and well established reality, where that protagonist changes everything, including the tone. Even if those have some tone changes and comedic elements, including in the middle of the fights, they are there because of the MC, as he's the source of the chaos and changes the reality around them in an interesting way. Chainsaw man also works in a similar way, we clearly have a brutal and merciless world and the MC with his silly motivations as a contrast. In Mashle, even if we remove Mash, we'll still have a non-serious world of magic with silly characters and loose rules. This, alongside with the unclear stakes, removes most of the tension from the serious moments, making the show fail at reaching its true potential.
I hope that the second season solves at least some of the problems, but it seems that the author just doesn't know what he wants his story to be.