Matt Addison, played by Eric Mabius, and Matt/Nemesis (played by Matthew G. Taylor) appears in Resident Evil and Resident Evil: Apocalypse.
Addison is an anti-Umbrella activist posing as a newly transferred Raccoon City police officer, who has sent his sister to work Umbrella Corporation to steal some information to expose Umbrella for illegal activity. When the T-Virus is released at the Umbrella "Hive", the Red Queen seals the Hive, killing everyone inside including Matt's sister. Matt is arrested by a group of umbrella operatives, led by One.
Along with Alice, he is then taken to the hive where they are met by a horde of zombies. Matt and Alice are separated and Matt comes across his zombified sister. Alice saves Matt's life, but he later becomes infected when they are attacked by a Licker. Matt begins to mutate, and Alice is preparing to give him the anti-virus when the mansion door bursts open and a group of Umbrella scientists take him. He is then put into the "Nemesis Program".
In Resident Evil: Apocalypse, Matt has been transformed into the mutation "Nemesis T-Type", programmed to eradicate all remaining STARS operatives. He tracks Alice down and they are forced to fight to the death. Alice realizes Nemesis is Matt and refuses to kill him. Nemesis joins forces with Alice and they defend themselves from a helicopter, sent by the Umbrella forces to kill them. However, in the ensuing battle, Nemesis (Matt) is crushed by wreckage and presumed dead. If he survived, he was killed when a nuclear weapon destroyed the city.