These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Badass Family: Shion is the father, Emma is the mother(not exactly Bad Ass, but being able to be three hours in the Holy Spring Luna implies that she is stronger than normal people), Luu is the daughter, Anise the older and smarter daughter and according to Shion, the dragon is the son.
Complete Monster: Shion's mother from the backstory. Sacrificed ten children to turn her younger son into a powerful demonic being and cast him out when the ritual handicapped him. Then she did it again using her older son and succeeded, turning him into a horrible demon. It's probably for the best that Faust killed her.
Harsher in Hindsight: Shion not being able to get the multiplication table right is funny until you find out that back in his childhood his physical and mental capabilities worsened after a botched Ritual.