Fratalin

 worked on Amethyst Viral Containment Station. He is a multiple entity made up of 800 individuals. He kept on talking about the Viyrans and their work. His voice is assimilated into their vocal banks. After Mila-Charley placed the Doctor unconcious he failed to create an explosion to stop the Daleks before the Daleks time conduits exploded. (BFA: Patient Zero)