black sheep
Evil root and evil child is a word, Pinyin is Ni è g ē nhu ò t ā I, which means the root of disaster, old refers to the bad son.
Idiom explanation
The root cause of disaster. The old refers to the bad son.
Source of allusion
The third chapter of a dream of Red Mansions written by Cao Xueqin in Qing Dynasty: "I have an evil root, and I am the" devil king "in my family."
Grammatical usage
As object and attribute.
black sheep
harmonious relation among emperor and his ministers - shèng jīng xián xiàng