For a start I have to say that I usually do not write reviews, so my point of view might be completely biased instead of finding "objective" qualities in this manga. I apologize to the readers of this review if this is not what they expect but I feel the need of expressing my thoughts after finishing reading.

I honestly do not care about being objective, or at least I do not seek to be too critical in this review. I only care to mention the reasons as to why I think this is a good read.

Toujuushi Bestialious (or simply Bestiarius) is a good manga, that I can assure you. It focuses on the times of the ancient Roman Empire, around the 1st century, and the twist is that there are not only humans, but also several types of beasts and other humanoid creatures. This allowed the manga to show other points of view on the cruelty of the Empire, and it also allowed the characters to develop bonds that would not be as special as if it was just about humans.

Plot wise I really liked it. It was a simple story: several individuals (mostly the beast races, although the protagonists themselves are humans) fighting against the seemingly unstoppable force that was the Roman Empire to achieve freedom and to find a place to live in peace. The manga had several protagonists and each of them felt nicely developed, especially the "main" protagonist Finn, although other characters like the Briton Arthur or the Roman Lucius were amazing as well.

On the more technical side, it presents a dark, detailed and gritty art style that reminded me of other works like Drifters or Berserk. I really liked it. The pacing and paneling were good, it was easy to read and it never feels like a slog. Despite it being a short manga, I think it achieved creating a good worldbuilding and likeable characters.

The fight and action scenes were very well done, and the level of detail was impressive. The thing the main characters have in common is them being gladiators at some point of their lives, which gives them an interesting way of fighting each other, as they develop brutal combat styles which are shown in every bloody battle present in the manga, especially those that happen in the Colosseum.

One thing I really liked as someone who likes the history of Rome is that Kakizaki depicted the Roman lifestyle in a very accurate way, especially when it came to the legionnaires' equipment. The gladius, scutum, pilum, helmets like the centurion's, every single detail was drawn carefully to be as historically accurate as possible.

Overall this is a very entertaining manga, I do think that anyone who likes both history and fantasy should read it, especially since it's a relatively short read that shouldn't take you more than a couple hours. Is it a masterpiece? Probably not, but I think it was extremely enjoyable. Is my rating objective? I don't think so, but I don't like to view things in an objective way as long as they make me feel the world and the characters I'm reading, and Bestiarius certainly achieved that.