When SEELE learned of Gendou betrayal they sent a team to kill everyone at NERV. In the battle Gendou takes Rei to the Central Dogma. Gendou then orders Rei to take him into Lilith, but she refuses and goes into Lilith alone. As Rei and Lilith merge a new huge creature is created, which floats towards the sky.
Profile: The Eighteen Angel may be considered the last Angel because she carried out what Kaoru did not. It was a merger of Lilith and Rei.
Fate: When she tried to merge with EVA-01 and Shinji, he broke free ripping a hole in her.
Notes: Lilim are demons born of Lilith.