User blog comment:FairyRaven/Fairy Tail Chapter 387: Tartarus Arc, Part 4: Father and Son, Review and Commentary/@comment-5593752-20140606115000/@comment-4829046-20140606122247

/gasp

Maybe he did. Maybe in the timeline that Ultear deleted, Zeref did revive him and somehow sent him to this one using his own magic! Nah, I hope that is not the case....