I really enjoyed hearing about what the weapons were made up of. Holy water in the sacred, and a blend of magic and alchemy in the gospel. I don't recall learning that in the anime.
I assume Rosette and Chrno are the first human demon relationship Magdalene knows about. They're curious of the effects but are also scared of Chrno, clearly with Kate saying it's worth it to risk injuring Rosette and Chrno to stop him.
Rosette is incredibly impulsive and irrational, I'm pretty sure I had this problem with the anime as well, but it's really questionable why such a sporadic young girl would be in such an important position.
Also not a fan of how a Magdalene scientist is a complete pervert on underage girls. Maybe I'm taking it too seriously, but his character feels like shallow comic relief to fill the pervert old man quota in this story.
I've loved both demon designs we've seen. This one was really cool with multiple faces and spider like body.