User blog comment:IamJakuhoRaikoben/Chapter 499: Gray and Juvia, Review./@comment-5668006-20160830040915/@comment-5303512-20160830093447

Just the way that it looks with Juvia's death is that she obviously transferred her her life force into the blood when she put it into Gray, so basically she lives inside Gray now, just like Ur lives inside the sea now.