User blog comment:Natsu11/Zeref and Natsu?/@comment-95.34.19.161-20130329133853/@comment-3177613-20130525124706

Zeref said that 400 years ago, he learned the value of life. Maybe it will be natsu who will use Eclipse to go back in time, that will explain how Zeref was transformed from a evil, dark mage to the self-loathing Zeref we know, and also how he knows of Natsu.