Sebastos Abdes Pantera is an agent for the Emperor of Rome.
In this case with the year being 54 AD, said emperor is the infamous Nero.
We are told in a blurb for one of the adventures, "Pantera, known to his many enemies as the Leopard, is the spy the Emperor Nero uses only for the most challenging and important of missions." As go passes in the life of this very interesting fellow, the empire will see the loss of one ruler and the ascension of others, briefly, and in no small way will Pantera play a part.
Pantera is the son of Julius Pantera, a decurion in a company of archers stationed in Judaea at the time we meet him. Though he was the bastard child of a relationship with a woman in Gaul, his father cared for him and kept him close as he was occasionally transferred around the trouble spots of the Roman Empire. "Since the day he could first walk, his father had taught him the secrets of the archer's craft and had instilled with it, as the food and drink of his son's young life, the twin bedrocks by which a soldier measured his own worth. First of these was his absolute loyalty to his commander: a true legionary obeyed every order immediately and without question. Second, stemming from the first, was the unblemished virtue of his own honour which required that he always bring respect and dignity to his position. Honour was everything." This would remain a constant in his life which would make doing some of the things he would be forced to do as a spy less than favorable in his eyes.
Our introduction to Pantera comes when he is a boy and he learns a terrible truth about his father, at least terrible to him, one that will make in him someone very unwilling to trust others as he grew up. Then the tale jumps ahead a good number of years and Pantera is already in the service of Emperor Nero as an undercover operative. He is pretending to be a disabled seaman and is doing an excellent job of it until one little slip would reveal the truth to an observant slave named Math: "Pantera, he of the bland hair and the not-bland face, had made one unconscious spring on to the dock with the fluid motion of an athlete, of a man who knows the fine tuning of his body, and cares for it, and can use it as a weapon in any way he pleases."