User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-67.176.158.104-20140207023318/@comment-74.110.105.73-20140207165011

I think Issei's new power up has something to do with his familiar, Ryuuteimaru, like it evolving or something, 'cause this volume will center on Rossweisse, a Valkyrie, and Ryuuteimaru is a type ship whose name I can't spell nor pronounce, and both are from Norse mythology, so it seems fitting.