User blog comment:IamJakuhoRaikoben/Chapter 323: The Shadow That Comes And Goes, Review./@comment-5444132-20130315231143/@comment-5551986-20130315235235

We dont know if he may be doing a neccesary evil. In the future he may have lost Froch or whatever his exceeds name is, due to his own weakness (The grief of losing his friends in the horrible, war ridden future may have given him a darker personality to help save his friends kind of like a Madara from Naruto in the Worst case scenario), possessing rogue and defeating Gajeel may have made him stronger, thus giving current Rogue the strength to save his friends, or he may have had an ulterior motive to empower Gajeel by pushing him to his limits. Unless in the next chapter he will openly oppose fairy tail, he isnt wholely evil yet. Besides the whole time travel things puts more or less, a loop whole through everything. And, i dont think Dragons are on the other side of the gate, i think there may be Zerefs Demons that may be used to distract the dragons, but considering its a cannon, that goes my theory.