User blog comment:CNBA3/Operation Face/@comment-5303512-20140702130002

Another reason why I added my theory why Lisanna would be a vessel for E.N.D is because maybe Hiro secretly was planning a way to kill her off, because he didn't want her to return but the Animators wanted her back because they liked her.

Maybe he would do it around the end because there wouldn't be much more purpose to bring her back other wise.