Magical Girl Lyrical Nanoha: Shamal has the ability to project her hand a long ways, which she uses to retrieve Nanoha's Linker Core. It looks disturbing enough as it already is, but then consider how it could be more violently used: to rip out someone's... brain? Heart? Spine? Penis?
Given how long the Book of Darkness must have existed, it would be statistically improbable to never have had male masters. If we assume, as we aren't given any reason to think otherwise, that its possession of a master's body always results in a female form, then what would happen to the males' family jewels? OHSHI-
The history of the Wolkenritter is one of implied horror. When they first encounter Hayate, they aren't used to being treated as people instead of servants bound to the whims of their master; as a result they become fanatically loyal to her. Think on what kind of treatment it would take to make them so cold and bitter and that three of them are young women and a little girl. Although, it might actually be worse to consider the alternative — that Hayate is typical of the masters of the book, and it's been wiping their memories of person after person that they've loved, leaving them cold, bitter shells.
Fate learned everything she knows about magic and combat from Precia's familiar, Linith and it's also implied that a familiar's knowledge comes mostly from it's master. Therefore it can be assumed that Precia has knowledge of magical usage in combat beforehand or gained it through extensive research.
