"Ahhhhhhhhhhh! Kill me... please!" The princess howled, as she was begging for Jin Rou to kill her immediately. This suffering was more than enough for her to know that they had kicked a huge plate this time. The burning sensation she was experiencing, that even her soul was being burnt out, was so excruciating that no matter how loud her scream was, it did not lessen at all. All she wanted was the relief of death.
Compared to the princess, Pingjing Hai had already committed suicide before the flame reached his soul, thus, he avoided this fate worse than death. He had no time to think of the princess' sake at all. After all, they were going to die. There's no reason and benefit for him to kill the princess immediately to avoid the suffering. Furthermore, he could not bring himself to use his hands to kill the princess. Thus, he chose to commit suicide by himself and left the world.