People might ask why they fully believed in Han Xiang's words... there was also a reason behind it --- not only because Han Xiang was Xiao Fang's good friend. It was also because of her handwritten blood letter.
There was a phrase that could describe this belief. 'Lies written in ink can never disguise facts written in blood' [1]. The tradition of writing in blood was especially present in Buddhism and the Han people were a full believer of this tradition. That was also why Han Xiang resolutely left a blood letter, despite the need to bear the pain while writing in between her last breaths.
Han Xiang wanted to tell the world the ugly truth of that disgusting man and she needed an irrefutable proof for them to believe her side of the story. Thus, she dared to take her life as a gamble. Besides, she couldn't live that long anyway. Why didn't she use her life to save other people's lives?