I don't think that he actually killed her, as in one of the chapters it shows him killing himself right after she died (?)
Well we don’t know the full story
Nah he killed her n then killed himself. From the hints it can be said the deal between him and the demon had something to do w needing to kill her.
Yeah it's a given the demon cant take a hold of her soul if she wasn't killed via su!c!de or something similar (mvrd3r). Thus he both did it right after he unalived girlie
There's no way Blake isn't Cain based on what we've seen.
So basically she's falling in love with the guy who killed her. Stellar. I'm outta here lol