User blog comment:JohnnyN64/END/Natsu theories don't add up/@comment-86.130.20.213-20150122140320/@comment-25032153-20150122230520

but Zeref has said that Natsu is E.N.D so it would mean that his demon powers and form is sealed in a book and he became a human but with fire magic this is why igneel choose to train him and how the dragon slayers were trapped was because they had really old dragons within them making their age being older then the Natsu was older then all the other dragon slayers.