User blog comment:FairyRaven/Fairy Tail Chapter 426: Black Heart, Review and Commentary/@comment-25111584-20150401185614/@comment-24.90.189.198-20150402041932

I honestly dont think Mashima spent that much time working out the details of the time travel, but, you need a timeline without an eclipse plan at all or or you have a grandfather paradox. Future Rogue cant go back and have them build the eclipse gate unless he is from a world that already has created the Eclipse gate without his interference.