Evangelion Unit-01/Bio & Battles

Evangelion Unit-01, most commonly refereed to simply as Unit-01, was produced by the Hakone branch of Gehirn as the Evangelion Test Type model. Unlike the other Evas, she was generated directly from the body of Lilith, and is consequently referred to as Lilith's "offspring" or "clone" (リリスの分身, Ririsu no bunshin). On a physical level, Eva-01 has the same characteristics as an Adam-based (i.e., any other) Evangelion, so the exact nature of her relationship to Lilith remains a subject of debate. Eva-01 received her soul as a result of the Contact Experiment with Yui Ikari in 2004, but was not "finished" until 2014.

As with the rest of the Eva Series, she was ostensibly created as a weapon to be used against the Angels, and she was the first Evangelion to face actual combat (against the Third Angel Sachiel). Eva-01 is infamous for going berserk and moving without any power supply (prior to the acquisition of the S² Engine from the Angel Zeruel). While Eva-00 has gone out of control before and Eva-02 goes berserk immediately before being destroyed, Eva-01 is the only Eva that has gone berserk in direct combat, to deadly effect.

Eva-01 is treated by the higher-ups at Nerv HQ, namely Gendo Ikari, with a suspicious favoritism. Once all of the Angels all destroyed, Eva-01 becomes the key to both Gendo and Seele's scenarios for Third Impact: the former intent on using her as an "ark to save humanity from the nothingness of Third Impact", the latter as a "medium" to Lilith, who has been rendered unusable by the loss of the original Spear of Longinus. The implication is that, by her unique creation, Eva-01 was intended as a "backup" for Lilith all along.