A.D 70 The mightiest empire Rome started conquering the world. The whole Europe was havocked by Roman's foot. In Ablion, in order to protect their homeland, the Bravest Wyvern fought a bloody battle against the invader.
The term Bestiarii (闘獣士) refers to those that fought against beasts, whether through voluntary combat or execution, during the Ancient Roman era. Bestiarius refers to a single Bestiarii.