This is my honest review.
I started reading a long time ago, most of the time it was to distract and disconnect, so now I have read many novels of many different genres, And I can say without fear of being wrong that there are very few novels that I have come to connect or more specifically immerse myself in the characters, some because it was too fast, others because I did not understand what the prota was going through (or the protagonist literally was a being without emotions or a cardboard pesonaje) or because the characters were not very deep or only followed the prota (not bad but, I think what makes a story memorable is to see that all the characters are 'alive' and that they are just as important as the mc), but that's not the important thing, when I came across mushoku tensei, at first I didn't like it, partly because of the personality of the protagonist, but it wasn't because of him that I stayed in the story, I stayed in that story because of the secondary/main characters, some with good development others that were only touched enough to get to know them, but even if they were only superficially touched they caused me to feel that they are alive and living in their own world. In my opinion I think what impacted me the most was the development of the relationships between the characters, at first I didn't notice it, in fact I overlooked it, but at one point I came to like them and came to understand them subconsciously, and seeing how ludy grew up was what hooked me into the story, I still remember how much I cried during the death of you know who, and also when he left you-know-who, those two events together with the various difficulties both emotional and the fights and their characters were what told me 'they are alive' just that feeling is what caused me to think about finishing reading that story, and this fan-fic is doing great, it is transmitting to me what very few novels achieve, they make the characters alive, many may not notice it, this may be for everyone but for me, who have read different stories since I was between 12 and 14 years old (currently 17) it causes me an impact, and even today it has been a very long time since a novel provoked such a unique sensation, for those who came across this story, I recommend it, although I understand that many do not like some genres like haren give it a chance, in the end it is not about how many women the main character has, but how they all grow together in one way or another. In the case of mushoku tensei it develops it well unlike others, in general both this fan-fic and the original novel are very good reads that I would recommend to read.
So much for my opinion, both of the fan-fic and the original novel. (google translator)