As Ryu had expected, Rinushka was quite powerful. But there were several things working against her that Ryu had seen through.
For one, she was too arrogant, and that was coming from Ryu. She really thought that just because she had her blade out like that, and that she was close, that his head was actually just on a platter for her taking.
Second, there was a Dao God right there. By default of Star River's presence, Lords and Sovereigns couldn't even begin to use their Control, leaving her unable to use her full strength.
Third, Star River couldn't affect Ryu's Control at all. That was because when it came down to it, if he was truly desperate… Ryu could always use his Childe of Order Constitution which would allow the laws of the world to work for him. As though that wasn't enough, he still had his own Inner World.
Rinushka had all of these disadvantages active before she even attacked.