Everyone has the right to be angry, regardless of their cultivation level or social status.
It's not to say that Lu Xuanji, being a "Half-Step True Immortal" of the Ninth-Layer Nascent Soul, and a highly respected elder in the Cultivation Realm, cannot be angry with Zhouyang, a junior.
In fact, he already has a very good temperament. Although he did take some small-scale revenge on Zhouyang, he controlled the extent well, not really harming Zhouyang.
If it were a cultivator with a bad temperament, who was inexplicably burdened with a great blame and forced to fight to the death with a peer, even if they had no strength left at the time, they certainly would not have spared the person who got them in trouble afterward.
So when Lu Xuanji brought up this matter, the unease Zhouyang felt due to being schemed against by him dissipated completely, leaving his face full of embarrassment and fear.
