Its formal name is Multipurpose Humanoid Decisive Weapon Synthetic Human Evangehon. They were built over the course of 14 years at The cost of astronomical expenditures in order to protect mankind from the Angels. They were constructed in utmost secrecy by the Special Duty Organization NERV, and their operation is left entirely to that organization as well The Evas can deploy AT fields, just like Angels, and also have the capability to neutralize them but eligible pilots are limited to 14-year-old boys and girls, who have no mother Normally, they function on the power supplied through the umbilical cable. In an emergency, they can sever the cable and operate on an internal battery, but that limits them to about 5 minutes of operability. The naming of the Evangelion is seen as having been taken from Adam's wife in the Old Testament, Eve,and the term "evangel".
In the anime/manga franchise Neon Genesis Evangelion, Evangelions, or simply Evas, are the mechas piloted by the children chosen by NERV. Although at first glance they appear to be giant humanoid robots, they are actually cybernetic, integrating a substantial mechanical infrastructure with many biological components. Their flesh is rarely seen, however, since they are covered in flexible polymer sheeting, armor plating, and restraints.