I really loved this chapter. Simple, but amazing!

I thought humans betrayed Acnologia, but to think that he used to be a man! That explains why Zeref knew Acnologia was arriving in the Tenroujima Island arc. I guess Acnologia just hates everybody.
Now, since we're learning more about dragons, could this be one of the reasons for the dragon's disappearances? We're they forced to leave by the king, or were they worried that Natsu, Wendy, and Gajeel might turn on them? I think it might be the first one, since in the anime (I think it happened in the manga too, but I'm not sure), I believe we saw Igneel watching Natsu, and Grandine talking to Igneel.