"I know. You want to ask me out. All the foxy ladies love my accent. It drives them crazy." — Carlos to Jill after their first encounter.
Carlos Oliveira (カルロス・オリヴェイラ,Karurosu Oriveira?) was a mercenary for the Umbrella Biohazard Countermeasure Service (U.B.C.S.). Oliveira held the rank of Corporal, and served in their Delta Platoon as rear security for Alpha Squad, where he was also their heavy weapons specialist. Nothing is known of Oliveira following the 1998 Raccoon City Destruction Incident, though it is known he survived the bombing.
"Looks like our roles have been reversed from the time we first met, huh?" — Carlos, upon Jill awakening after her fight with the Nemesis.
A man of mixed Latin American and indigenous origins, Carlos was an active member of a Communist guerrilla organisation fighting in an unnamed country in South America. After government forces wiped out his faction, he was scouted by Umbrella Corporation to join their U.B.C.S. force, which was actively recruiting terrorists and other criminals. His expertise in heavy weaponry and vehicle maintenance made him a valuable asset.
"Calm down, lady. I'm no zombie! My name's Carlos."
On 15 September, the U.B.C.S. was mobilised and prepared for a large-scale operation in Raccoon City, which was undergoing a t-Virus outbreak. Four platoons, measuring at approximately 120 men, would arrive on 26 September, by which point the outbreak had spread out of control due to contamination of the drinking water.
Though many mercenaries were killed or mutated in the opening hours, Oliveira survived in a scattered team led by Delta Platoon's CO, Cpt. Mikhail Viktor. Accounts differ as to whether they made their base of operations on a tram or a subway train, but both agree that their intent was to make the vehicle operational again to facilitate an evacuation from the city. On the night of 28 September, Oliveira met former S.T.A.R.S. officer Jill Valentine, who was on the run from the Nemesis-T Type, and recruited her into their team tentatively for their mutual assistance.
While in one telling of events Oliveira travelled out with the team, in another, Oliveira and Bravo Platoon Monitor Tyrell Patrick were given orders to search the Raccoon Police Station for Dr. Nathaniel Bard, an Umbrella virologist leading their vaccine research effort within the city. This investigation turned up blank when it was found he was at the Spencer Memorial Hospital instead.
In both events, however, Oliveira reached the St. Michael Clock Tower, where Valentine was attacked and infected by the NE-α Type parasite. For two days following the attack Valentine was left in a comatose state, and Oliveira searched the Spencer Memorial Hospital for the vaccine being worked on. In two accounts, it was here that Oliveira witnessed Patrick's death, either setting off a booby-trapped safe while searching for the vaccine research or killing himself with a hand grenade to take Sgt. Nikolai Zinoviev with him when he turned on him. In a third account, however, Patrick worked with Oliveira in keeping the hospital operational, and died later. In all accounts, however, Oliveira succeeded in treating Valentine with a dose of the vaccine.
By 30 September, emergency radio and television broadcasts warned of the Presidential order that a missile be fired at Raccoon City. Oliveira went off on his own searching for a way out, either finding a helipad at NEST 2 or by heading to Incineration Disposal Plant P-12A. There are, as well, multiple accounts as to what transpired here. In the NEST 2 account, he assisted in seriously injuring the Nemesis- T Type by immersing it in treatment fluid and took off with Valentine in a helicopter after a standoff with Zinoviev. Of the P-12A accounts, one claims he met up with Valentine at a helipad on the other side of a scrap yard and piloted it out, while a second claims he picked up a radio transmission from ex-S.T.A.R.S. officer Barry Burton and the two were picked up by his helicopter.