Su Biyu was a woman of many talents, all of them having to do with her favourite activity, murder. Now, as she had to obey the Flies' orders, she was usually forced to interrogate her targets or spy on them. Of course those required her to learn some actual skills that weren't just slashing around with a sharp blade.
She became extremely good at hiding in the shadows, and she also became able to tell when one was lying. Of course she couldn't use her skills on actually skilled individuals, but Uma wasn't exactly trained for those types of things. She was strong, yes, but never had any experiences with interrogations, and as such Su Biyu was able to use her rather dark skill to tell Jian whether or not the woman was lying.
It was exactly why Jian was now conflicted. Because after talking for close to an hour, Su Biyu revealed by glaring at Uma for the hundredth time already, that Uma hadn't told a single lie.
