Okay. WHAT?!? It was

Nina?! I... eh... uh... WHAT
[url]http://tvtropes.org/pmwiki/pmwiki.php/Main/TheDogWasTheMastermind[/url]
EDIT:
Oh wait... so that was why ! he couldn't kill her in the first chapter.

Aha!... I guess.
EDIT EDIT:
Oh! And that's also why

all the monsters, e.g. those of the tentacle persuasion, never killed her!

I think it makes sense now! OMGGGG!