Kenja no Mago? I thought it was really interesting at first, reading the synopsis, unfortunately nothing "new" or original, nonetheless enjoyable.
Let's jump straight into the review and find out why.

Story (6)
As the synopsis say: Shin our main protagonist had a boring life, that's until an accident happened and he died. Reborn in an alterative universe, as a child he was casually saved from a hero. That hero will teach him magic and his other friends will teach him the art of the sword, meanwhile he has the knowledge of his past life and has an incredible magic power. You guessed right, he's OP af.
He was raised in the jungle so he doesnt know nothing about this world, thats why thanks to the help of the king himself he joined an accademy to make friends and learn about this world (medieval).

Art (8.5)
The manga overall is well done, nice and dynamic art, when needed very detailed, the background most of the times are also well done, so the art is one the best thing of this manga.

Character (6.5)
I could use just one word to describe them: cliché.

Enjoyment (8.25)
It really feels like an other: School, harem, fantasy, magic manga/anime, If you notice I didnt put comedy, that is because there's nothing really funny about this manga.
Dont get me wrong I really enjoyed reading it, but the comedic aspect really lacks in my opinion. There are also hint of romance and a bit of action, the pacing is allright, it doesnt make feel the manga boring, but than again this is just the beginning so I could not say for sure that the pacing will be always good as it is now.

Overall (8)
If you are looking for a strong male protagonist, a bit of romance and action, surely later there's gonna be a lot more of action, this manga might work for you.

Have fun!