Basilius is the third supporting antagonist of Ryse: Son of Rome and a son of Nero - he is just as psychopathic as Commodus and arrogant, enjoying a life of excess and women while also believing himself untouchable due to his social status.
He did, however, care for Commodus and wished to free his brother from the Picts - however he had little regard for the soldiers who would risk their lives to do so, indeed he openly scolded the Commander simply for daring to question his cruel treatment of the Britons.
Indeed, Basilius' treatment of the Britons was barbaric and dishonorable even to the Romans, proudly crucifying captured slaves and flogging others while men, women and children alike were treated as nothing more than "dogs".
Basilius reasoned that he did this because the Britons could only understand violence but his smile and capricious temper showed that in reality he did most of this because he enjoyed seeing others suffer.
When Commodus betrayed the Briton King and murdered him in front of his own people, sparking a riot, Basilius fled alongside his brother - reportedly the pair selfishly stole a boat along with their guards "throwing women and children aside" to ensure their own survival.
Later in the game Basilius would suffer the same fate as his father and brother, being pursued and killed by Marius - a lone soldier whom the Imperial family had wronged via the murder of his entire family.
However before his death Basilius was tricked into allowing Marius (under the guise of Damocles) to enter the arena to face Commodus - he also made a fatal hubris in showing Marius a gift to his father, which was similar to the legendary Brazen Bull torture device, as Basilius calmly explained how the device worked he finally realized Marius' true intents and was stabbed to death by the soldier for his dishonorable actions.