Who do you think is the worst parent

Among the nurse fathers, who do you consider the worst parent to Ryoshu based on the flash backs and how they treat their own apprentices?

Valencina and her physical abuse?

Matthias and his neglectful fun dad energy?

Dihui Star’s verbal abuse?

Rien’s sociopathic manipulation disguised as love?

The Maestro? Just in general the maestro.