Oleg Petrovsky

Oleg Petrovsky is a Cerberus general introduced in Mass Effect: Invasion. Petrovsky is an experienced and formidable soldier, but is also well-versed in military history. Viewing the path that humanity is taking and the looming danger of the Reapers in that context, Petrovsky is concerned about humanity's future and strongly supportive of Cerberus' plans.

Mass Effect: Invasion
As Aria T'Loak defends Omega from the Adjutants, hostile Husk-like creatures unleashed on the station by a Cerberus transport ship, the Illusive Man dispatches General Oleg Petrovsky and Colonel Raymond Ashe to aid her in containing the threat. Petrovsky is in command of a powerful starship called the Elbrus, which he uses to decimate the remaining Adjutant-controlled Cerberus ships surrounding Omega.

When first encountered by Aria aboard the station, Petrovsky is euthanizing a turian who had been badly wounded by an attacking Adjutant. Aria accuses Petrovksy of butchering aliens, but as a nearby salarian transforms into an Adjutant, the general points out that what he is doing is a necessity; killing those who were attacked is the only way to stop them from transforming.

Petrovsky then asks Aria to gather together what help she can provide the Elbrus so that they can defend against the next wave of ships, which will likely have much better weaponry, until Cerberus reinforcements arrive. When Aria asks if he will make a last stand, like how he lasted against a turian assault for several weeks when he was a corporal, Petrovsky explains that the strategies he's using were chosen because the makers of those strategies lived. As more Adjutant ships enter Omega's space, Petrovsky vows to lift the siege.

The Adjutant ships quickly overwhelm those defending Omega. Petrovsky takes the Elbrus through the Omega 4 Relay, reasoning that they can be stopped at the source: Cerberus's Avernus Station. Petrovsky, Aria, and a Cerberus squad clear the station out, but Aria overexerts herself with biotics and passes out. The Illusive Man orders Petrovsky to restrain her and drop her off at a research station so that Cerberus can take over Omega virtually unopposed; without Aria's leadership, the fragile peace between Omega's gangs splinters, allowing Cerberus to move in. Petrovsky complies, but begins to express suspicions about how the Adjutants were released. He is not pleased with the possibility that so many of his men were lost to only further a ruse.

During the return trip to Omega, Aria breaks free and forces Petrovsky to take her back with him. Petrovsky warns Colonel Ashe in a coded message that the Elbrus has been compromised, but Ashe's preparations fail to catch Aria and she escapes into the station, where she quickly unites the gangs against Cerberus. In the following battles, Petrovsky and Ashe come into conflict, with the General appalled at Ashe's disregard for the safety of his own troops and civilians.

When he realizes that Cerberus has no hope of defeating Aria on her own turf, he comes up with a plan to get her to talk. Aria has a plan of her own and designs an ambush to distract Petrovsky's forces while she slips into the Afterlife Club to contact the Illusive Man. Thinking his superior had failed, Ashe triggers a trap in Afterlife: he remotely releases an Adjutant in the building to kill Aria. Petrovsky expresses outrage that Ashe would endanger Cerberus's troops and the station's civilians, but Ashe argues that they are acceptable losses. They struggle briefly before Aria hurls the Adjutant into them. It infects Ashe before Aria finishes it off. As his subordinate transforms, Petrovsky kills him to protect his men.

Now that he can speak with Aria, Petrovsky reveals that he has already won the battle for Omega. He had evacuated most Cerberus forces earlier so that the fleet surrounding the station could open fire and destroy it in the event it could not be secured. He gives Aria two options: she can continue to fight and be destroyed with the station she cares for so much, or she can accept exile and surrender Omega to Cerberus. Knowing that Petrovsky will back up his threat, Aria concedes. Petrovsky finally secures Omega for Cerberus. In his report to the Illusive Man, the General asserts that Aria was most likely killed and turned into an Adjutant, and Colonel Ashe is missing and presumed dead. He states that he hopes this victory will help spare the lives of his soldiers in future battles in the defense of humanity. Afterward, Petrovsky reflects on his last conversation with Aria and predicts that one day, she will return.