The Ramiel Virus, aka The Blue Song Plague
The Ramiel Virus originated from human contact with the inert corpse of Ramiel itself. A sub Angelic being similar to Iruel lived on the outer surface of Ramiel's body, and when the human harvesters attacked the body, the virus attacked them in return. A hive collection of organisms slightly larger than blood cells, the individual viraii convert red and white blood cells into a crystalline material exactly like the surface of Ramiel. The crystals begin converting the entire human body into two types of crystalline material. The outer surface material emits varying pitches of hums and choir chords, (leading to the name Blue Song Plague), and a red semi crystalline matter that forms a soccer ball sized S2 engine. Over the course of 17 hours, the host is formed into a perfect copy of Ramiel albeit the size of a small car and with a slightly weaker AT field. As more humans (alive or dead) became infected either from Ramiel itself or from contact with another infected, the virus became near airborne. As large groups of infected gathered together, the amount of the virus in the local atmosphere allowed it to function as if airborne. Citizens of Tokyo-3 sought refuge in the impregnable might of the Geofront as hunting packs of the infected began razing the country of Japan with lasers, encountering minimal resistance. What followed was a 13 day battle between the legions of infected, a squad of heavily armed humans in Sub-Eva Titan suits, and Evangelion Units 14-19. Humanity eventually prevailed however the virus had become so condensed in the air that the entire group not inside an Evangelion was infected. We at Geofront Labs designed a inoculation that could suppress and piggyback infect other humans. Therefore, every citizen simply acted as a carrier for the virus with each human they encountered becoming a carrier as well. Eventually the entire population of earth had a dormant sample of the virus in their blood. Therefore... We are ALL infected.