User blog comment:IamJakuhoRaikoben/Chapter 456: Order, Review./@comment-67.5.245.122-20151011202022

I've noticed several similarities between Lucy/Natsu and Mavis/Zeref such as Natsu and Zeref doing the head butt with future Lucy and Mavis respectively. Mavis and Lucy both hug Natsu and Zetef respectively. Zeref and Natsu both carry Mavis and Lucy in a bridal fashion respectively as well. Both brother (more or less) fell in love with blondes. The girlies seems to some extent is the opposite of their lovers such as Lucy's celestial spirit magic to Natsu/Ends fire dragon/curse power as in heaven and hell and holly to demonic. Zeref can create life while Mavis can create elustions that are not alive and Zeref is alive but immortal where Mavis is basically a ghost and dead. In short Mavis and Lucy are the light to Zeref and Natsu's darkness respectively.