User blog comment:Stone Roger/Natsu and Zeref have somekind of relation?/@comment-110.143.150.135-20150516073230/@comment-116.102.69.168-20150518114651

[SPOILER] Newest chapter has comfirmed that Natsu (at least his body) is Zeref's brother. Zeref was desperated in bring his brother back from death cause he died as a child. Zeref want to die so he created E.N.D with his dead brother's body, hoping he could be strong enough to end his life.