Sextus is shown to be a charismatic Showman for his own Gladiatorial stable. Through suggestions off his step-sister, Claudia, Agrippa is recruited into Sextus' family of Gladiators to help save his father, who has been falsely blamed for the murder of Julius Caesar.
Initially Sextus is proven to be a worthy ally, teaching Agrippa the ropes of being a Gladiator and always offering advice towards Agrippa's latest match. As the story progresses however, it is revealed that Sextus is a pirate who is hell bent on revenge against Rome, more specifically Julius Caesar, who killed his father.
Sextus will learn of Octavianus through twin assassins sent to him offering the contact against Octavianus, who is the true heir to Julius Caesar. Sextus accepts and will abandon his post at the stable to hunt down Octavianus. Claudia will also go on the search for her brother, leaving Agrippa's room mate, Damma, to sort out all the preparations for the Gladiator Games.
Sextus eventually locates Octavianus and sends two large brutes to deal with him; but Octavianus manages to hold his own by setting the brutes trowels aflame with a torch. Claudia arrives soon after to then try and talk sense into her brother, and at the very least help Octavianus escape.
Sextus isn't heard or seen of afterwards till very near the end, were he unleashes a large scale assault on the coliseum just after Agrippa beats Antonius, who was revealed to be the true mastermind behind Julius Caesar's assassination.
Agrippa, now given back his rank as a Centurion soldier, gives chase along with Claudia leading them to Sextus' ship. Sextus first knocks Claudia unconscience leaving Agrippa to fight one on one against his former mentor. Agrippa will triumph against the pirate, much to the dismay of Claudia, but it will be Antonius who kills him via a collapsing tower, that is shot down by one of Sextus' own battle ships, that lands on Sextus.