Shadow of Rome
Octavianus is a good friend of Agrippa, and co-protagonist of Shadow of Rome.
Octavianus is the first of the two to learn about the tragedies that occur around Julius Caesar, including his assassination, his murder being pinned on Agrippa's father, Vipsanius, and Agrippa's mother to also be executed in light of her husbands crime.
Agrippa goes into a rage to try and save his mother, but to no avail as Decius kills her while Agrippa is busy handling the guards. Agrippa is essentially labelled as a traitor to the country and is forced to exile himself. Through the suggestion of a newly founded ally, Claudia, Agrippa becomes a Gladiator to at least attempt to save his father, whilst Octavianus will subtly try and solve the mystery through stealth and infiltration.
Through the guidance of one of Caesar's most respectable advisor's and lieutenants, Pansa, Octavianus improves upon his skills of stealth. Through sneaking, using disguises, knocking out guards and/or witnesses from behind with vases, crawling through small openings and shimmying across small crevices on the walls, Octavianus is able to infiltrate such high security placements as the Senate House and Antonius residence.
Octavianus' investigation manages to bring forth many interesting facts, such as Caesar's assassination to be undertaken by a group of individuals, not just one, and with a great deal of Rome's most powerful politicians to be involved. Initially Octavianus believed Marcus Brutus, Cicero's protege, is the culprit, after learning of Caesar's last words being ''and you too, Brutus''. It is eventually discovered through evidence that the Brutus that Caesar was referring to was Decius Brutus, not Marcus. Marcus is still implicated, as are many other individuals, which was founded by Antonius, and then murdered one by one by Decius, ordered by Antonius.
Behind the scenes, Agrippa's gladiatorial boss, Sextus, is both running his Gladiator Stable while also planning on killing Octavianus. He was given the contract by two twin girls who work under The Mistress, which Sextus gladly accepted with it falling into his plans on destroying Rome as a means of revenge for his father being killed by Caesar. Sextus will encounter Octavianus whilst he is searching for Marcus, ambushing him with two massive brutes. Octavianus manages to hold his own by setting their trowels on fire, and Claudia arriving to hold off Sextus for Octavianus to escape.
Once safe Octavianus delivers all of his accumulated evidence to Maecanus, Antonius' secretary, who also was conduction his investigation into Caesar's murder, Maecanus ''detains'' Octavianus only so he can have him disguise himself as Julius Caesar.
During the finals of the Gladiatorial games, with Decius and Agrippa fighting, Macaenus arrives with the ''Julius Caesar'', which out of shock forces Decius to uncover his assassination towards Julius Caesar. Knowing that Antonius was also not the appointed heir, the false Caesar asks Antonius what he is doing on his throne. Antonius filled with anger and confusion also lets slip at knowing he wasn't Caesar's appointed heir. At this moment, Octavianus takes off his disguise and is simultaneously revealed to the people of Rome to be the true heir of Julius Caesar.
Antonius orders Decius to kill them all, furthering the proof over his role for the whole affair, with Agrippa besting both Decius and then Antonius right after. After Agrippa's victories, though, Sextus will launch an assault upon the coliseum, taking Antonius who is to help with the destruction of Rome, with Agrippa following in toe.
Agrippa now once more a Roman soldier begins chase after Sextus with Claudia, eventually with the two battling it out on board Sextus' ship. Agrippa manages to beat Sextus also, but with Sextus dying under a collapsed tower which was shot down by Antonius. Now with only Antonius left amidst the unravelled mystery, Agrippa and Octavianus invade his fleet with Agrippa heading alone to Antonius' ship. On board, the two once again fight with Agrippa once again winning. This time Antonius is down for good as he manically falls of the edge of the ship into the water with his wounds.
With all the blood shed finally over, Octavianus, as the true heir to Julius Caesar, appoints Agrippa as his General, with Claudia opting to travel instead but insists she'll return to witness the ''new'' Rome.
Similarities to Metal Gear Solid 2's Raiden
Octavianus has many resemblances to Raiden from MGS2, with his skills in stealth, his long blonde hair, androgynous appearance, and for being mistaken as a member of the opposite sex by other NPCs.
It may act as a tribute, or just a funny set of coincidences, though neither CAPCOM or Konami have alleviated on either possibility.