User blog comment:Uraharattack/Theories and Predictions, NO FAN FICTIONS/@comment-3290324-20150609214715/@comment-5303512-20150611042626

There has been a theory that Hiro's use of the number 7 has led to some sort of misfortune. Since Erza is the "Seventh" Guild Master, there might be some sort of tragedy to befall her or some thing like that.