I don't get it at all

You didnt get it? have you evr seen evangelion? Or is it the multiple Kaworus?? If you didnt understand the last the author explains is a delusion she/he made, like eveytime Kaworu died in the series or the film was replacd by another one who shared memories and had a new personality but their wish to make Shinji happy was there
Its a bit confusing but I love it cause I just can get over Kaworus deaths TTvTT why you have to dieeeee

They didn't watch/read it.