This is a hidden gem.
It really is, the only reason I made an account is to add a review for this. This comic is unlike any other manhua, it's not one where the mc struggles his whole life, suddenly gets a powerup, suddenly changes his whole personality and suddenly everyone wants to challenge his strength. Although this story, in the beginning, has some strength-testing it ends once they realise that the mc is a demi-god; the twist? Mc isn't aware.
The characters are fantastic, the story is well written and intricate, but easy to understand, and the art is fantastic and complements the grim/fantasy theme of the story. It's like a slice of life mixed with isekai escapism. This is and always will be my No. 1 Manhua. I will recommend this to anyone, anytime, any chance I have. You need to read it.
The mc gets transported to another world with a library that he owns which has every book in existence. He is a sort of health guru to his customers, they come to him, vent out their troubles and he offers solutions alongside a book to make profit. The thing is, the people of his world are not the people of earth.
In this world, there are secret magic societies, black mages, knights, dreamworlds, elves etc. And a lot of people complain about how the mc is oblivious, but it is hinted at multiple times that this magic society is kept secret. The mc offers advice to the people that coincidentally actually helps them in their magical endeavours, but that wouldn't be what makes the people who challenged his strength believe he was a dem-god.
You see, the books he has are magical. Upon opening them you will receive enlightenment and reach a new height in your magical endeavours. And that's where hijinks ensue, why are you still reading this review, READ THE MANHUA!