This protagonist kills so many people that Yagami Light in Death Note looks like an amateur. But this protagonist does NOT kill specifically bad guys. He's not a hero. He can let serial killers and mass murderers continue to kill innocent people, as long as he himself isn't attacked. Having the power to save people doesn't mean you have to save them. That's why I love this story. He saves himself and his close friends, but he doesn't care about strangers. He kills when it suits him, he saves when it suits him, and he ignores when it suits him.
Story: It is Isekai, but this story is original enough to actually make it good. The simplicity of it is the best. "Become great enough to join our side". That's more or less what the Gods of the world told the class that was summoned. They tell them what great deed the students must do. And as of volume three, that's still what the plot is. It might very well change later on, but for now, we can enjoy a very simple story about trying to become one of the God-like beings. Well, kind of...
But the main character and his uncompromising attitude is still the best part. He doesn't kill one person, he kill thousands. And he can kill anyone. Gender, age or physical appearance doesn't matter. And while this story might sound psychotic, it's surprisingly logical. The thought process of the protagonist is describe in such a clear way that almost all of the killing is perfectly justified.
Art: Almost no fan-service. For me, that's a great relief. Isekai is usually full of fantasy babes, but this story has manage to avoid that pretty well. But I still cannot say that the illustration are the best I've seen. They are good enough.(mandatory hot spring scene is here though, so some fan service)
Characters: The protagonist is kind of boring. He kills people without even reacting. It's like stepping on an ant, or killing a fly. The Female main character however is spectacular. She tries to use reason and think of ways to avoid slaughter, but eventually just sighs and ignores the deaths happening around her. But my favorite, a fat bastard that cries when he might be killed, and then when he is safe-ish, he becomes an annoying ass that complains about everything. It's a great character. And it shows that the author is not scared to make these pretty realistic bastards without exaggerating too much. While there is some over-the-top characters, most of them are well made. And without spoiling, there is such a big amount of unexpected reveals about the classmates. Even three volumes in, you get those "wait, he/she was a **** all along!?" moments.
Overall. I freaking love (almost) this story. Because it breaks the norm. It dares to be different and do things that you don't always see. There's no hero or antagonist. Everyone can be good or bad depending on the situation. And while the protagonist is a "little" bit too overpowered, it's written about in such a way that there's no way you get tired of it. But a lot of characters die, so many new ones are always showing up, it might become too much like a "new enemy ever episode" kind of thing.