It was not only his beast form, but his chaos armor was also coming to an end. To make matters worse, his HP was not in the best condition. He had received many hits. Without his Nine Yang Restoration, the damage he suffered remained. His HP bar was below half.
Despite his anger, an urgency to preserve his life came to the surface. But that urgency was soon doused when he remembered he had the immortal soul. The unwillingness to bear the shame of fleeing from these people he deemed to be beneath him made him stay. He continued to fight ferociously until his chaos armor expired.
He still couldn't use the Nine Yang Restoration. He also couldn't flee with his three opponents blocking his way. Not that he wanted to flee, though. His pet was occupied by Murong and Oswald, unable to come to his aid.