User blog comment:The ultimate bigfoot/dragon civil war arc/@comment-26350059-20150804140627

I've thought about this as well but my thinking was that Acnologia is not as villainous as we may think. He and the other dragon slayers turned on the dragons because there was a bigger threat. Maybe there is like a 1st dragon that is in hiding laying eggs so that someday all of the dragons would return to reclaim earth from the humans. Acnologia and the other dragon slayers turned to make themselves more powerful to battle that dragon and the only way to do so was to become a dragon. Come to think of it what makes Zeref think that Acnologia is alone? What happens if he decides to join the battle between Fairy Tail and the Alverez Empire and he comes with all of the Dragon Slayers that turned on the Dragons over 400 years ago. Who could stop them.