User blog comment:Uraharattack/Theories and Predictions, NO FAN FICTIONS/@comment-25693405-20150611143348

I love the crackpot theories, but I think Erza is as immortal as Zeref. (The reason I think she survived the tower of heaven is that they physically couldn't kill her). If Acnologia joins the battle, he's going to attack both sides, neither side would engage him if they had a choice.