@megido-rev.M: Science IS magic! And Magic IS science!! Different names for the same thing.
Start of Episode 7? I noticed something that wasn't so evident in the manga:
HUGE SPOILER!
His little sister IS Yaya! That big-titted woman made a "bandoll" (or three of them) out of dead humans ...which seems to be a new concept. That would explain a lot of things... seriously! A LOT of things!
Of course it's just my idea

Nothing in the manga suggests this, afaik. Yet. I've read up to 33.5 and then stopped.
I liked the manga, but I'm
really liking the anime!
Edit: Ok, I want to point out that I had only watched the first minute when I posted this.
By the second minute?
Someone outright SAYS YAYA is a "bandoll"! DAMMIT! I don't recall that happening in the manga...
So I'm 2 minutes into episode 7... what else could happen?