The Multi-Purpose Fighting Machine which NERV has built in order to combat the giant Angels. These giant robots function through a cerebral-nerve link with their operators. The pilots connect through the A10 neuron system of the brain. They can connect through their plug suits and the medium of liquid known as LCL.

Normally, they draw on external power provided through huge umbilical cables. However, when necessary, they can run on internal power for a limited number of time. Five minutes if they are in standby mode and one minute if they are full-active mode. This shortage in power has been solved when EVA 01 managed to engulf an Angel's S2 Engine, making Unit 01's power supply unlimited whether connect through an external cable or not.

Currently, the Evangelion robot is the only machine with enough ability to cancel out an enemy's AT field.They use a wide range of weapons from a Prog-Knife to a Pulsitron Rifle. In the course of the series, Ryouji Kaji explains the importance of the Evangelions.

Kaji said that if at any time an Angel comes in contact with Adam, who is beneath NERV headquarters, the disaster known as Third Impact woudl occur. The only ones with the power to stop the Angels are the Evangelions.

Dr. Ristuko Akagi also stressed that the "armor" of the Evangelion is actually Bindings which let them control the Evas. Without the bindings, the Evangelions are very difficult to control (if fact, beyond human control).
She also stressed, that Evangelions are man made by other men and that they have no human souls within them. Man did something and found God.

"When they picked-up God, God became angry and punished man. God disappeared. So man, tried to make God with his own hands: Adam. And man created himself in Eva." Adam's alter ego and Lilith's minion" - Nagisa Kaworu.