User blog comment:B214/Light Novel Volume 16 spoilers/@comment-1392308-20131021165434

I wonder how Rizevim found out about Chichigami. Perhaps Issei lets it slip or something.

I'm looking forward to seeing how pure blooded vampires fight so this is going to be interesting. Hopefully they're skills aren't skipped over like the Grim Reapers were...(we only know they fought with scythes, nothing more).