Xiong Jie had been overjoyed about the deaths of his two enemies since he thought his life would be smoother and better after this. However, he did not expect he would die as well before he could even enjoy his life. Moreover, he had died at the hands of his own 'people'.
Duan Ling Tian could have stopped one of the three Great Guardian Warriors from killing Xiong Jie if he wanted to but he did not since he did not plan on letting Xiong Jie live anyway. They were just taking advantage of each other. Duan Ling Tian killed two of Xiong Jie's enemies because Xiong Jie had led him to the three Great Guardian Warriors. He was not obligated to save him from his own kind. Moreover, he would never be kind to the Boar-Devils who had killed many of his people.
The Great Guardian Warrior who killed Xiong Jie glared at Duan Ling Tian and said viciously, "How dare you, a Human-Devil, come to our Boar -Devil's territory… It seems like you're tired of living!"