User blog comment:B214/High School DxD EX/@comment-172.56.21.143-20150809084245/@comment-108.224.166.119-20150809141821

If it's because his son has a BG that doesn't mean he's dead it could be a replica or even issei may have fully mastered the BG in the future and can now "give" it or let people "borrow" the BG without any negative side effects that's just a theory though