User blog comment:NaiflidG/Discussion on Cain (possible spoilers)/@comment-5619706-20131222171907

Like I posted in the Talk Page of First Born, the title "Father of Murder" alludes to the actual biblical Cain, brother of Abel. If the writers don't get it straight, I don't know what's wrong with them.

I'm mulling over the holidays to see if I'll give Season 9 another chance, and if I do continue watching, I would need to be really impressed by the two episodes. Not just one of them, and I don't want them to just be good. I need them to be awesome. Abaddon as a Knight of Hell was an amazing episode, Cain's introduction should step it up a notch.