Mo means evil, and that's the name Prince Sun Mo has and there is no way that Sun Qiang wanted to name his child such a thing, but he has to due to some circumstance.
And that's the reason why Tao Xiurong said "What can you expect from someone who has the name Mo" as Prince Sun Mo suggested to battle in the night which is not allowed and considered evil.
Her words, "Your father couldn't protect his name" meant Sun Mo's father name, Sun Qiang, and its same name that is given to Xiong Qiang, the youngest son, as Sun Qiang lost a battle against Xiong Song
. . .
Chiyou knows what Tao Xiurongs words meant and they were all wrong and disrespectful against his friend.
And Chiyou considers Sun Mo as a good person so he cannot accept her words and he is angry.
He could also hear the laugh of citizens and many other humans around them
Thus, he shouted "Xiurong!!!
You have spoken too much, and it's better you say sorry now or feel sorry later"
