Imagine dragons flying in the sky

It all started with the 7 years the Fairy Tail mages were trapped in Tenroujima. The Fairy Sphere worked, but it trapped Acnologia with them, separate but lurking around for the opportunity to break free. Natsu's own protective bubble inside the spell can be accessed by him from time to time, though, so in his boredom they end up talking. Natsu has a bit of a crisis about Igneel, about this foreign power inside himself that only grows as time goes on and the fact that originally, he may not be from the same time as the rest of his friends. Acnologia hadn't meant to grow attached to the little shit with pink hair. Really, he hadn't. But there was this something the dragon slayer had that seemed familiar to the dragon of the apocalypse, for some reason. And, well, dragons were curious beings, previous humanity non-withstanding.