i don't get the end
What's there to get? They just have a tag-a-long.
What end? this guy can't put sense in his manga to save his life. there's really nothing to get
What isn't there to get? Killy protects the child born from his girlfriends fucking each other after he blew them off for thousands of years and then it eventually saves the world, as NSE and Blame 2 show.