User blog comment:CNBA3/Chapter 405 Review/@comment-24622358-20141020122652/@comment-24930767-20141020134006

i'll go with something related to Minerva, Erza or Kyouka. one of them manipulating ace by fusing with something or the other. but the Lumen Histoire seems not probable because it means nearly 'Light Story'. so i doubt it would be about a girl in a crystal. . . But it is Mashima, so anything is possible.