User blog comment:IamJakuhoRaikoben/Chapter 445: The Ugly Fairy, Review./@comment-26451407-20150721060304/@comment-4829046-20150721084450

Also the fact that they are currently in a new timeline. Zeref seemed to be fully aware of the changes when he was viewing from afar and only in this timeline did he make the decision to return to his empire and start the extinction. In the one F-Rogue viewed, Zeref probably hadn't done anything or made any decision and indirectly that would mean everything that happened with Acnologia in these recent arcs never happened either. Zeref would have just let Acno do his thing. Face would have been in the works regardless and I feel but Acno may have obliterated the Demons instantly in that time. Then again, the timeline thing was a botch-up by Mashima anyway so this stance is sadly very weak. My point is that Zeref's decision is an important factor in the fabric of the FT universe.