User blog comment:Miskos3/Chapter 478: Stealth, Review/@comment-24784846-20160319155222/@comment-24546844-20160319183531

What I get from that (apart from the possibility of loli stripping event in the near future) is that Mavis plans on using Zeref's magic against him somehow, just like Natsu and Lucy did with Jacob's.

I've been wondering if Zeref's Death Magic empowered by Fairy Heart (a magic from the "dead" like Igneel's) wouldn't be strong enough for him to kill himself along with Mavis. If so then she can just willingly give FH to him and manipulate him on using his magic maybe?