Complex sentence: Rei leads Shinji through the ruins of the GeoFront into NERV Headquarters, where he is reunited with his father, Gendo Ikari who informs Shinji that he is there to pilot a new Evangelion, Unit-13, alongside Kaworu.
Split into simpler sentences: Rei leads Shinji through the ruins of the GeoFront into NERV Headquarters, where he is reunited with his father, Gendo Ikari. Gendo informs Shinji that he is there to pilot a new Evangelion, Unit-13, alongside Kaworu.