To start things of, "Bestiarius" was a read I greatly enjoyed. The story overall is not the newest invention of storytelling, however, it is easy to follow and and the smaller stories combine greatly to one bigger picture.
The characters are well written, which I noticed mostly in the antagonists of the story. The author did an awesome job in making characters likable and, of course, hate-able. Even though the manga was a rather short read, with 54 chapters (7 mangas), I felt a solid connection and involvement with the characters, what happened to them and how they saw every part of their storyline.
Most importantly....the art. The visuals in "Bestiarius" are absolutely outstanding. Each and every single panel of this manga is filled with astonishing quality of artwork. The big shots as well as the smaller, more detailed pictures. It had a great supporting role in making the characters hate/ likable, because the looks on their faces were portrayed really realistically.
In total, I rate this with an 8/10, especially with the monumental artwork!