Following the deaths of three in 1995, the decision was made to have Lisa killed, seeing her as no longer being of use in their research. Following the execution, her body was observed for three days to confirm her death.
Especially with the first game, you could get Barry killed by the end, but that ending is non-canon. For the scenario with Chris, it is never really revealed what happened with Barry after they reached the mansion. His path is never mentioned again, and not even in subsequent games.
The Progenitor virus (also known as the Clay virus) was an ancient RNA retrovirus with the ability to mutate DNA and recombine genes to strengthen a host's characteristics but cause detrimental mutations or death when cells developed abnormally. Humans adapted to the virus were known as "Progenitor Humans."
Ustanak is a highly intelligent B.O.W. that appears in Resident Evil 6. This monstrosity was created by Neo-Umbrella for the express purpose of hunting down Jake Muller. It is considered to be the most intelligent and resilient bio-weapon ever produced. Its name is derived from the Serbian word for "revolution".
Crimson Heads are a type of zombie (named V-ACT by Umbrella) and can run, jump, and sport small claws.
Sherry Birkin is a character from the Resident Evil series of survival horror games. She first appeared in Resident Evil 2 as a helpless child in peril, she later returned in Resident Evil 6 as a capable adult who could handle the dangerous mutations in her own right.
The Golgotha Virus, abbreviated as G-Virus, is a genetically-engineered species of virus within the Progenitor family. While the t-Virus typically causes cellular necrosis in infected organisms, the G-Virus is able to repair dead cells and bring its host back to life, effectively granting biological immortality.
It is also revealed that Ada is in fact a spy sent to steal the G-Virus from an unknown organisation. Ada is assumed dead after saving Leon from a zombie attack. Leon, Claire and Sherry manage to defeat both William and Annette and escape Raccoon City before the airstrike hits.
The T-virus can't bring somebody back from the dead, but it does reanimate dead tissue within infected hosts prior to death. The G-virus causes spontaneous mutations, such as what we see with William Birkin and Curtis Miller. The G-virus can bring people back from the dead.
A third eye on some part of the body (typically the shoulder) was a common feature of creatures imbued with the G-virus. The virus infects cells close by, turning them into so-called "G-Cells". These G-Cells then produce more of the virus, which will spread further across the body.
What the hell happened with the G-Virus? After Birkin attacked both USS soldiers, the vials containing the G and T viruses were destroyed, relasing them into the sewers and the city's water supply, infecting the inhabitants of the Raccoon.
Wesker returns in Resident Evil 5 conspiring with the pharmaceutical division of the TRICELL conglomerate as a means to create the "Uroboros virus", an enhanced virus derived from the Progenitor virus, with which he ultimately plans to release into the Earth's atmosphere.
The Raccoon City Destruction Incident - Six weeks following the Mansion Incident, the T-virus began to spread through Raccoon City due to a combination of contaminated run-off from the mansion leaking into the city's water supply and the release of the virus in the city sewers after a botched operation by Umbrella
Humans infected with the C-Virus mutate into B.O.W.s known as J'avo. Those infected with the C-Virus undergo a self-combustion of sorts upon death due to their abnormally high body temperature; this is also believed to be an effect inherited from the T-Veronica Virus, which gave its victims flammable blood.
The viral outbreak in Raccoon City was caused by several actions by Umbrella employees - one release of the T-virus in Raccoon Forest, and another release of the G-Virus in the city.
X is a Tyrant, one of the most infamous monstrosities in the Resident Evil universe, while the Nemesis, a different enemy in its own right, is created largely from the body and physique of a Tyrant. But Mr. In fact, the full name of the T-Virus is actually the Tyrant-Virus.
During the Raccoon City Incident Umbrella saw it as the perfect oppurtunity to wipe out the S.T.A.R.S. members that survived the mansion incident of RE1 who could reveal to the public what Umbrella was really up to. As such they programmed one of the remaining Nemesis to track down and kill the remaining S.T.A.R.S.
After Jill rings the bell in the Clock Tower she has to fight the Nemesis because he destroys the helicopter that was supposed to get her out of the Raccoon City. Becuase it's all in Jill head, she's hallucinating due to virus and none of the events since the player takes the control of the Carlos actually happen.
