Evangelion Unit-01 is the second Eva ever created. Eva Unit-01 was a test type. Eva Unit-01 is special though. It has the determination of humans and is a clone of Lilith, the Mother of All Life. Eva Unit-01 had gone without power or energy several times, proving it is unstable, and can go berserk at anytime. An Eva cannot generate S² organs but Eva Unit-01 took in one when she ate the 14th Angel, Zeruel. Eva Unit-01 has been the most unstable evangelion of all. Going berserk several times, it is very dangerous. Possessed with the soul of Yui, Shinji's mother, Eva Unit-01 always shall help Shinji when he needs it. That is the true purpose of why it goes berserk.

Eva Unit-01 was not created by man, but is a copy of what they found in Antartica. Eva Unit-01 refuses to allow anyone or anything but Shinji Ikari to pilot her. Eva Unit-01 has literally refused them. Shinji Ikari has been taken into Eva Unit-01 before. The LCL of Eva Unit-01 turned Shinji into a state and substance much like the premorial soup. In other words, the LCL changed Shinji into a substance that we cannot see. Eva Unit-01 holds many secrets, and the most bizarre thing ever happened to this Eva is when it's Awakening happened. It was simply barbaric, the way the Eva ate the angel. The Eva acted like a beast. It's abilities are far more stronger when it had Awakened.