When the Queen of Pain attempted to ambush the King with the deception of her death, Gilgamesh had survived her treachery through the protection of Avalon, his defensive noble phantasm. However, when the newcomer arrived, Gilgamesh stopped. He was about to make a jarring statement about the resilience of mongrels and how he was about to euthanize her; to put her down like the mad beast she was when he stopped. 

From arrogance to fear, the King changed. Before him was two entire separate things: On one hand, his one and only true friend, Enkidu was before him, in his glory as the only man recognized by the king. On the other hand, however, the only being who had ever fought him to a standstill was here, and he was not looking like he was carrying reason. 

However, when he saw Enkidu confronting Mia, he came to an understanding. 

[i]It seems that Enkidu wishes to challenge her... understandable.[/i] Gilgamesh smiled a little. [i]It appears that our glorious reunion will have to wait. [/i]

And with that, the King of Heroes stepped back to allow the berserker in the form of his one and only friend to take the fight.