Just to comment on the criticisms of this manga: I think that the beginning chapters are seen as a bit bad mostly because the Main Character can be a bit unlikable. To list some examples: Seth (the MC) has pissed on people, called a villain gay, and can be a bit of a prick. Now, if the author meant to make the MC a rash, lovable idiot (like Luffy) this would be bad writing. However, I think the bigger problem is that he breaks shounen tropes in ways that are often a bit uncomfortable, though I'd say Seth's actions are more accurate for an immature not-so-innocent teen. I'd mostly chalk this up to the French writer.
That said, this manga really hits its stride when it focuses on story arcs and other characters. I think if you start reading under the assumption that you're not supposed to like the MC, the start is far more tolerable. The art is great. The character design is great. The world is interesting and seems fairly complex. The storyline so far has a few decent surprises without ever seeming cliche. Personally, I ddon't mind MC and recommend you try reading it up into the Rumble Town Arc to see if you still like it.