User blog comment:Stone Roger/Natsu and Zeref have somekind of relation?/@comment-120.28.163.2-20130906131145

Okay I'm gonna go out on a limb here and say that natsu went back in time 400 years were acnologia first came into being and natsu met zeref they fought but during the fight natsu realized zeref has good in him then zeref realized it too so he told natsu to kill him as punishment for all the bad things he had done but natsu wasn't strong enough so he promised zeref one day he will be strong enough before somehow getting back to his time. That is how Zeref knew natsu when the 2 met at tenrou island