The cause of the Fourth Impact is the removal of two Spears of Longinus from Lilith by Shinji Ikari, the two impact triggers Kaworu Nagisa and Shinji Ikari, Kaworu being demoted to the thirteenth angel, the destruction of Lilith's body, and the release of the Twelfth Angel from the Mark.06, which awakens Evangelion 13 after it eats the angel, thus causing the Fourth "Impact".