This listing is pure pedantry by the powers that be in managing the database. There's not even 5 true chapters in this "series". Übel Blatt changed publishers after the first few chapters, so they were packaged up with some sketches and sold as "volume 0", even though it's actual main story content, and not a prequel or side story. You won't even see this listed as a separate series on reader sites, it's just chapters 1-3 (one will have a lot of extra pages that are counted as the other 2 in this "series"). As for the story, it's literally the first chapters to Übel Blatt,so it's the exact same bit as the rest of it, quality and otherwise. It's a good story, but very much has that "rushed shounen ending" that finishes the main storyline but leaves a few loose ends and would be better if they added a few chapters of denouement.

Like the waif that gets picked up relatively early in the series has a fake name made up for her and it just sticks for the entire series, like she would never try to get them to call her real name.