User blog comment:IamJakuhoRaikoben/Chapter 388: Erza vs. Minerva, Review./@comment-24053170-20140614051148/@comment-4829046-20140614054418

When did you get that END has never met him? Also curses were discovered to be a thing only in this arc. We have no idea if Zeref's magic is actually curse power or not. Or maybe he has both curse and magic(likely case) since he is the one who presumably created curse power in the first place.