User blog comment:Stone Roger/Natsu and Zeref have somekind of relation?/@comment-98.24.173.177-20141217232023/@comment-68.103.118.155-20141221004138

Actually, he's not natsu's dad, he's his creator, more than that, he is his strongest creation, when they met zeref hoped that he would kill him, but for the time being he wasn't strong enough to do so