User blog comment:FairyRaven/Fairy Tail Chapter 407: All for My Demise, Review and Commentary/@comment-4896357-20141101160604/@comment-7418318-20141101212000

Sure Zeref said that stuff about Natsu killing him, but then he also said "Will it be you or END who will reach me." implying that they are seperate beings or at the very least difference consciousnesses.