I can see Ciel and Hope getting some personality from their reaper parents in their interactions with each other.

Like Ciel kind of just cuddling up to Hope and not letting her argue. Hope being like Will and being like "wtf you little pest." Ciel only ends up curling up closer when she says that. And Ciel's just like "stfu. I'm your brother. I'm allowed cuddles." Than Hope just mutters under her breath "more like sister with those looks" and Ciel just glares at her and is like "well if it fucking takes being your mother fucking sister to get fucking cuddles, than fuck it."

Granted the role of big-sister-little-brother is swapped, but

That's basically most of their interactions

I just noticed how much it was like their reaper parents.