TLDR: This is so bad that is funny to watch.
Character 5/10
The characters here would make you go holy fuck this is so bad that is funny. So you have this guy named Anos the main protagonist that is a former Demon King who has been reincarnated. He is so fucking overpowered to the point that he can speak and turns straight towards adulthood after being 2 weeks old. He can also fuck you up and kill you with just his heartbeat alone. You can picture him as Saitama from OPM but has magic that can solve anything. He has everything such as Bitches, power, wealth, and you name it but instead, he chose to live as a modest student with overwhelming power. I don't know why but with this overwhelming broken power there are still people in this world that still challenge him to a 1 on 1 fight and somehow most of them are at the academy where he resides. Aside from that other characters are typical shonen cliche characters that aren't very interesting and quite predictable.
Story 4/10
There was once a demon king who had overwhelming power and could gain and control everything in the world. However, one day he decided to settle a promise with a Hero that this Hero will kill him and gain peace throughout the land. And the next time when the demon king reincarnated they will be as friends, not enemies. Until centuries later he was reincarnated. He is so broken upon his reincarnation that he can speak and turns straight into his original form as a 2-week-old baby. He can even fuck some dude up with just his heartbeat alone. To be fair most of the time is all about the demon lord who just wants to have a decent high-school life however upon his world there is much racism and discrimination at where he is. And those who view themselves as a higher class for the demon always decide to cause trouble or challenge him even though he is basically a god.
Animation 7/10
So everything is well animated that's for sure but my god it is funny to watch when the fight scenes drops from 60 fps to 30 fps. That is how the animation looks like. They look well when there isn't any fight but looks like garbage when the fight actually starts.
Conclusion
I won't lie this is funny even though is trying to be serious however most of the time the story is too ridiculous towards the point that is funny such as the Demon king is so strong and everyone knows it. Yet there are still some people in that world still DARES to challenge him. The animation for the most part is not bad but when it comes to the fight it does look downgraded.