User blog comment:B214/Volume 21 info & spoilers/@comment-99.118.13.217-20160613135349/@comment-94.5.128.78-20160613181713

It was established important characters don't die in this series in Volume 7. Someone from Vali's Team, Ria's or Sona's peerage except for Issei, Vali, Rias and Asia could have been killed by Loki easily or by his pet wolves.