User blog comment:Miskos3/Fairy Tail 540: Balance, Review/@comment-24053170-20170617230528

After reading this chapter and considering whats been happening, I am starting to wonder if this series will possibly end with Natsu and all the other first generation dragon slayers being returned to their original time of 400 years in the past.

Since they are currently in a space were time doesn't apply in the same way, and it was created by initial opening of the Eclipse Gate that brought Natsu and the others to this era.

So the only way to fix the problem and truly close the ravines for good may be to have them sent back in time.

Though I could be totally wrong on this, it does seem like that may be the best way for Mashima to end this series without turning it into a complete disaster...