User blog comment:Miskos3/Fairy Tail Chapter 472: Laxus vs. Wahl, Review/@comment-86.66.207.24-20160209095755

One thing is clear with this arc and August said it, the Spriggan are pawns, but for what reason ? I don't think it's to capture Fairy Heart, even if Zeref wants it, I don't think it's for killing Acnologia, so I have a theory :

And if Zeref wants Fairy Heart to pwer up the remaining Eclipse gate, maybe learning there is an Heartfilia left made him change his mind, using Lucy to change History once and for all by killing Acnologia before he turned into a dragon.

And here my second theory : and if the dragon who killed Zeref's family was Acnologia