User blog comment:IamJakuhoRaikoben/Chapter 482: Vigor, Review./@comment-4449950-20160419084318/@comment-24546844-20160419134201

I don't see why Hiro feels the need to give a backstory to Erza this late in the series. Not everyone needs a complex background that links them to the main plot and Erza definitely doesn't need one. She's just an orphan that happened to join FT by chance. Her life began at Tower of Heaven (where she becomes Scarlet) and was "renewed" at FT (where she becomes Titania). Everything else was built in panel. We don't even need to explain why she's so strong because we have a BS reason for that already. Nothing Hiro links her to would be so special that would feel amiss if it was left out, but on the other hand it would open space for more stupid things and unnecessary questions.

The best outcome I can think of this would be if Neinhart is mistaking her for his dead loved one who for some reason can be brought out by Historia.