To be honest, for me, this fanfic is quite a unique work. Why? Because I haven't found anything that I would really appreciate there, and yet it is still good enough to continue reading. It's strongest side definitely lies in the humor. It also has quite nice fights; it is extremely well measured in strength proportions and isn't scared of bold ideas.
About its uniqueness, it lies in terms of morality. It wouldn't be a lie to say that there is none. I mean, I wouldn't ever consider that those characters that appear could ever become main cast, but here we are. Even the protagonist's personality isn't that of a hero, antyhero, or anything you could ever expect. His personality feels as if he were born as a thug in Danmachi and later studied some math in our world, learned some of our culture, and went back to Danmachi. That also makes the story take many unconventional turns.
That makes the story interesting, but sometimes the story is uncomfortable to read, yet even those moments are often laced with comedy. I would say that this story is quite grotesque. Often mixing comedy with dark humor. I certainly wouldn't recommend it to people weak mentally.
I would like to complain about pacing though. Often it is all over the place:
At first, the whole system stood as a quite hard-to-beat wall of text. I know it was necessary, but some fragments were hard to read, as if a professor took something quite easy yet decided to make that as hard to understand as possible.
At first, fights were much more dynamic. And I know it's mostly because he had much easier enemies to deal with, but some present chapters are literally a fight to a fight to a fight. Often with additional POV change that makes it all even more tedious. That problem got even more obvious to me after the last chapter that literally made me happy because it slowed the tempo, even though I'm not a fan of the whole development—I don't like which characters the focus is on, I don't like the protagonist, and I don't even like his abilities, yet I am still here, standing on the edge of the cliff, with a beautiful view, but dirty pants because of the height.