User blog comment:Stone Roger/Natsu and Zeref have somekind of relation?/@comment-203.104.11.2-20130530085944

I really think he may be Natsu's father. They sorta look alike, and Zeref, when he see's Natsu on Tenrou Island, says something about being able to see him grown up.... I hope he is anyway, since Natsu doesn't have family members (other than Igneel).