User blog comment:Wrath022/Chapter 524: Black Future, Review/@comment-2214433-20170225111656/@comment-7418318-20170225141830

Maybe August doesn't know about Zeref wanting to kill all Humans. If he only knew about Zeref wanting to kill Acnologia it would explain how August could see Zeref as a saviour... albeit one that doesn't care about collateral damage.